7. ‘ 41.9.07. 2.. EH :.nl..........._.: ‘ll‘ \| ||I || II‘| |||| I - I l /- 79/01 em “a lllllll‘lflll l llllllll Michigan State University This is to certify that the thesis entitled An Introductory Chemistry Unit To Prepare High School Students lor Human Physiology presented by Marie Eileen Rediess has been accepted towards fulfillment of the requirements for . Interdepartmental degree m ‘ffirotogical Science Master of Science Major professor I)ate 0-7639 MS U is an Affirmative Action/Equal Opportunity Institution PLACE ll RETURN BOX to remove this checkout from your record. TO AVOID FINES return on or before date due. ll DATE DUE DATE DUE DATE DUE n lVfiF—Tl—l MSU Is An Affirmative Action/Equal Opportunity Institution AN INTRODUCTORY CHEMISTRY UNIT TO PREPARE HIGH SCHOOL STUDENTS FOR HUMAN PHYSIOLOGY BY Marie Eileen Rediess A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Interdeparmental Biological Science 1989 ABSTRACT AN INTRODUCTORY CHEMISTRY UNIT T0 PREPARE HIGH SCHOOL STUDENTS FOR HUMAN PHYSIOLOGY By Marie Eileen Rediess High school students entering Human Physiology before taking chemistry have difficulty understanding topics that refer to the molecular level of function. They also have little skill using laboratory equipment and procedures. In order to correct this, a chemistry unit was developed to overcome these deficiencies in the students’ backgrounds A five to six week base unit with expanded laboratory activities was developed to enhance the understanding of chemistry and illustrate the practice of science to the students. Each topic was covered from several approaches to increase the interest and broach individual learning styles. A pretest and posttest were given to assess the impact of the module on learning. Although analysis of the posttest compared to previous years showed no significant improvement, other evidence shows that students retained the information much longer, used it in other units and understood chemistry’s relevance to their lives. Students learned use of laboratory equipment and were able to apply what they learned to unfamiliar problems. Overall grades improved following the study. AKNOWLE DGM E NTS I wish to thank the generous help and support of my committee: Dr. Clarence H. Suelter, my chairman, who convinced me that not only could this project be completed, but that I would make a good "guinea pig"; Dr. Howard H. Hagerman, who taught me all I know about parasitic worms and statistics; and Dr. Martin T. Hetherlngton who has been guiding my career since undergraduate days. Without their inspiration, I would not have had the courage to begin this work. I must also express gratitude to "the second year NSF gang" Michael Brundage, Mary Fowler, Van Mchlliams and Tammy Voss who sweated out the summer of ’88 with me revising laboratory activities and teaching ourselves how to revise. The seeds of this thesis were planted at a molecular biology workshop funded by NSF at MSU. This workshop was put on by Drs. Hagerman, Hetherinton and Suelter, along with Dr. Glenn Berkheimer (who provided the teaching methods I use today). This program eventually expanded, through the concerted efforts of these people, to a three year program and what seems like an almost effortless way to get a master’s degree. Without these workshops and the National Science Foundation who funded them this thesis may never have been. Last, but not least, I wish to thank the school board and administration of Algonac High School who have so generously supported me with facilities, students, funding and release time. ll 13 28 40 154 165 TABLE OF CONTENTS Body of Thesis Introduction Student Transformation Instruction Evaluation Reflections Reference Pages References Consulted Glossary Appendix Appendix Appendix Appendix Appendix Appendix Appendix Appendix Appendix Appendix 111 112 113 117 123 131 141 149 (_.H : Unit Outline for CDQ'UI‘JUOW)’ Topic Outline for Previous Years 1988/89 Behavioral ObJectlves : Testing Instruments Student Interviews : Student Survey of Chemistry Importance : Test Score Data : Computerized Analysis of Multiple Choice Portion of Tests Item Analysis of Post Test Laboratory Exercises "Atom" Lab Black Box Labs Acid and Base Lab Discovery of pH Using Common Household Substances Biological Materials as pH Indicators Floral Pigments: Spectal Analysis and pH Dynamics General Effect of Salivary Amylase on Starch Effect of Temperature on Activity of Salivary Amylase Appendix K: Copies of Overheads Used in Lecture Further Reading Ill LIST OF TABLES 10 Table 1, Tally of Student Answers to Interview iv 31 31 31 35 35 35 38 Figure Figure Figure Figure Figure Figure Figure \IO‘UIAwNH LIST OF FIGURES Pre Test T Scores 1988 Post Test Standardized T Scores Linear Regression of Pre Vs. Post Tests April Test Standardized T Scores Pre Test Vs. Post Test Scores, 1988 Post Test vs. April Test Scores, 1988/89 Three Year Grade Comparison of Chem Unit Introduction Human physiology is a complex and varied study of homeostasis. The body is wondrous In its intricate and diverse mechanisms. We teachers must show students the dynamic balancing act that bodies must go through to maintain this balance. We must also show what can go wrong when this balance is lost. Most of this balancing act takes place at chemical levels within the cell. Students who study physiology need to have a basic understanding of how chemicals behave before they can truly understand, instead of merely memorize, how their body works. At Algonac High School, when money was in short supply and there weren’t quite enough teachers or hours in the day to provide a complete offering, physiology was taken in the sophomore year. It was the only bridge between biology and chemistry for college preparatory students. Chemistry was perceived as a Junior course. Now that the district has more resources, the science department has tried to change the image of physiology to that of a Junior or senior course. This has met some success in that there is now an equal mix of sophomores and upper classmen in the course, but many students are still coming into the class with little or no chemistry in their background. The first three years that I taught this class, the chemistry unit (see appendix A for outline) was two weeks or less as suggested by a curriculum guide developed by the district and science department staff. However, the students’ performance was not satisfactory when anything that required a chemistry background was covered. The kidney is probably the most difficult unit for the students to understand. It includes diffusion, movement of positive and negative ions, filtration, osmotic pressure -- all things that rely on a chemistry background. In the 1988/89 school year, five weeks were spent on chemistry. A week each of study on the heart, kidney and end of year pig dissection were cut to make room for the extra material. Lectures were supplemented by labs and labs were supplemented by lecture, but most of all we practiced. Everything was presented in two or three different ways. Often we would have more than one lab covering the same concept. I had hoped that using more labs to develop the concepts of basic chemistry would have a quantitative effect on the students doing the exercises. This idea seems intuitively right. And for the last fifty years or so (Hounshell 1989), this was the practice carried out in the classroom using various methods to present the lab activities. The science teaching reforms in the 60’s and 70’s kept the idea of laboratory activities being necessary in the classroom, although the reform labs tended to be “discovery“ instead of “confirmation“ labs. Discovery labs are wonderful fun and an excellent educational opportunity. The students learn so much about how things work, although I’m not sure that the concepts meant to be enforced are the ones that are retained. There are several methods of conducting these discovery labs. One method is to state the purpose of the activity for the students, and then have them decide on materials and procedure that will verify (or disprove) the hypothesis. The other method is to give them material and equipment to ’play’ with and let them design the lab from scratch, including the hypothesis. A third method is to give the students purpose and procedure while having no idea of the actual outcome yourself (but the succeeding times these labs are used, teachers must pretend lack of knowledge or else change the purpose or procedure). While these design labs are pleasant for both the student and instructor, and really let students see how things are happening, they use up a lot of class time. Ample time must be allowed for student modification. Students are rarely satisfied with their first, second or even third try. 80, while experimentation is a good thing, a design lab once in a while is about all the time we can expend. I end up intersperslng design labs with lab exercises to be sure the concepts I’m trying to deveIOp actually are being developed. At this point in time, researchers have not completely examined whether lab activity is more effective than other methods at strengthening students understanding of the subJect matter (Blosser 1988). So far, there has been no significant statistical evidence that laboratory exercises are any better than lecture in changing achievement or attitude. Bdosser wonders whether we are looking at the ’rlght’ variables to test. We do all these labs and then try to pigeonhole these skills to a written obJectlve test which is not designed to evaluate the skills learned in laboratory activities. I believe (but have found no supporting evidence in the literature) that labs increase problem solving ability, analysis skills, patience, coordination and encourages independent thinking. These skills are useful in any classroom or career, but are difficult to test obJectively. Laboratory activity certainly gives the students an idea of what science as a career can be. As i-lounshell states that the first obJective of lab work is “to enhance students understanding of the subJect matter....The second obJective of lab work should be to produce more scientists....If lab work is to produce more scientists, then teaching lab skills is essential. If these skills aren’t taught it will be like trying to train chefs without letting them into the kitchen.“ We do need more scientists -- by the Zist century the U.S. will need 130,000 to 700,000 scientists and engineers (Hetherlngton 1989). It will be up to us, as science teachers, to provide students with the excitement and perseverance to pursue these careers. Student Transformation Having a chemistry background before physiology is supported by most authors and publishers of physiology and biology texts. The texts that I have evaluated and used; Kilburn and Howell’s ,Exglgning__Life__Sglenge, Morrison’s et al W, Otto and Towle’s Mgdenn_Blglggy, Tortora and Anagnostakos’ Principle§_gf W91. Vander’s et al Human Womb. Welnreb’s Anatgm1_ang_2h1§iglggx and others; include a chapter on chemistry near the beginning of the book. The only variances seem to be the depth of detail the student is expected to learn. The topics covered in books aimed at both the high school and Junior college market varied little from book to book. The books intended for high school use only, however, povered little, if any chemistry. All the books for both the high school and Junior college market cover elements and atomic structure. Most texts discuss lipids, nucleic acids, proteins, carbohydrates, ATP, molecular movement, concentration, acids/bases and pH scale. Some cover reactions and molecular bonding. One text (Tortora and Evans Principles_gf_fluman_Ehyslglggy) had a chapter on physical principles such as motion, simple machines and properties of matter. With such universal adherence to a theme, can we avoid the same theme in our teaching if we expect the students to understand their own bodies? Of the physiology texts surveyed, most included chemistry in an early chapter, some Just before the cell, and some Just after. Of those that did include chemistry, almost all put the structure of the atom first. Since all bonding, and hence reactions, are based on how the electrons combine, this would seem the logical place to start. The proton and its mass was first discussed, then the neutron, and then the electron, although some did not adequately stress that the electron is for all intents and purposes, massless. Atomic number was then introduced, as well as mass number. Some books (including our text Tortora and Anagnostakos) still insist on using the not-quite accurate term, atomic weight. The one misconception that seemed to exist in all but one book (Vander et ai 1980) was the simplified Bohr model of the atom; a central nucleus with concentric rings around it indicating electron paths. Some would start the chapter with a three dimensional drawing of a very simple atom and then revert to the Bohr model. The Vander text showed only three dimensional drawings, including one with two electron energy levels, although even that one did not go into the proJected shapes of the p orbital. The Bohr model, even though not the current model of an atom, is very easy to use to show and predict electron transfer for bonding. After the atom was introduced, molecules with formulas and then reactions and equations were presented. Some texts then introduced osmosis and diffusion while others went straight to inorganic and organic molecules. Inorganic molecules always included water, and nearly always acids and bases, along with pH and buffer systems. With our society’s increasing reliance on technology and recent scientific investigations in the headlines of the daily papers, it seems rash not to include basic chemistry in every students background. The chemistry unit was taught from September 12 to October 15, 1988. Before teaching the unit, an evaluation test was given. A similar test (37 identical obJectives with 10/11 obJectives covering same concept; see appendix D) was given at the end. Analysis of the pre and post test scores showed that there was less than 10" probability that increase in scores were due only to chance. On April 3rd of the following semester, a test identical to the post test was given again to check retention. No specific mention had been made of chemistry before the test, and the students were not aware that they would be given a test on that day. Analysis of the post and April test results indicated that there was less that 0.001% probability that the correlation between scores was due to chance. I interviewed nine students on the fifth and sixth of April about the chemistry unit. The students were selected by computer generated random numbers. The randomness of the selection was modified by absences and volunteers who asked to speak after they saw others interviewed. One of the two students with low grades was absent both days and the other refused to be interviewed. The students who were interviewed have an average of C or better. The interview questions (appendix E) were designed to determine what the students remembered most from the unit, what had been most helpful with the other work, what was easiest to learn and what was most difficult to learn. They commented on the appropriateness of the length of the unit. They were also asked whether they thought the unit should have more or fewer labs and whether it was easier to learn the material from the d! 10 book or whether the laboratory exercises facilitated the learning process. Table 1, Tally of Student Answers to Interview Topic I Atoms I Bond— I Buffer I Chem- I En- I For- IPeriodicI pH I Syn-I I I Ing I system I lstry Izymeslmulas I table I I boIsI Runflnr I I I I I I I I I I man I I i I I I i I I 2 I 2| 2 I Mat I I I I I I I I I I helpful I I I I i I i I I 2 I 3 I I Easiest I I I I I I I I I I talcum I i I I I I i I i I I 3| _I Hardest I I I I I I I I I I talcum I I i I l I I I l I 3 I I I When they answered (see exact text in appendix E) what they remembered most or found most helpful or easiest, pH was the big winner. They apparently liked working with indicators and testing because they are so colorful. It is also a topic that I consider especially exciting. Others thought that the symbols, elements and/or periodic table was outstanding. Another girl mentioned enzymes, several times. Remembering the names of the formulas, compounds, symbols and “things“ seemed to be the most difficult. Most of the students interviewed thought the length of the unit was about right, although one student wished it were shorter, and another would have liked it longer. Three of the eight students thought there was an appropriate amount of laboratory activity, although 11 one suggested that it might be better spread out a little more; two students favored having more labs, while three said fewer would be better. Two of those three also said that they learned better from the text than from labs and the other said labs were better for helping them learn. One other student said the text was easiest for him to learn from, even though he could see things work in a laboratory exercise. The rest of the students said they got more out of the labs than they did the text. The students in this class are outspoken and independent. I believe that the opinions are their own, given without thought as to what might please Teacher. I also ran a survey on how important chemistry concepts might be in their lives. Not surprisingly, even though they all plan to go on to college, some even in the science area, they didn’t think chemistry was very important in their lives (see appendix F). The topics they thought would be most important in their lives would be salts and the maJor organic molecules; carbohydrates, lipids, proteins: none of which was remarked on (with the exception of enzymes) in the oral interviews. A significant number also cited the elements or periodic table to be of value in their lives. It seems they remember the 12 colorful and/or spectacular things, and think they will use topics that are much in the public eye -- diet. Instruction My mistake the first couple of years was to think that the students had (or would remember having) many of these topics in their previous biology course. I considered the chemistry chapter to be a review. After all, someone else had taught this, and I should not have to. Every year reinforced the fallacy of my thinking, the students Just didn’t do well on topics that required a chemistry background. In 1986, an introductory biology course was added that covered plants and animals instead of the cellular and human biology of the advanced course. 1987 was the first time that I had a combination of students from both courses in the physiology class. I had expected the advanced biology students to do much better -- they already had the basics and would only be adding detail while the introductory biology students would have to learn it all. To my surprise, there was no difference in performance between the two groups. All the students appeared to be learning anew. The chemistry 13 14 studied in their previous advanced biology course was not being retained. That’s when I decided to expand the chemistry unit from one or two weeks to five or six weeks. After much thought, and study of the text used in the course (Tortora and Anagnostakos i987) and other supplemental texts, I decided on the chemistry topics that would be most useful for my students understanding of human physiology. There were many things that they had to be comfortable with before they could begin to comprehend the cellular behavior of their bodies. (See detailed outline in appendix B.) In designing the chemistry unit, I had to keep two things clearly in mind. One, would .a longer unit really benefit the students’ understanding and achievement in physiology? Two, would laboratory exercises enhance that achievement? In order to understand the kidney, one must have a firm knowledge of both passive and active transport. To realize what is happening in a neuron, one must know the ions as well as how they can be expected to react with their surroundings. To understand blood chemistry, one must first know what a buffer system is as well as how it works to maintain equilibrium. One must also have some picture in one’s head as to what equilibrhhn is. Tb assimilate all these concepts, one must certainly know 15 about atoms, elements and molecules and how they work. With these things in mind, I designed a unit that would include the chemical concepts that the students would later need to understand cellular workings of the body. Besides covering chemistry concepts, I hoped to give the students analytical skills. I think that. given a set of data, any student should be able to draw logical conclusions from them, even though those conclusions may not be what we, as teachers, expect. I also expect that the student will be able to clearly state these conclusions, in writing, in a fashion that will make their thinking clear to the reader. I wanted to develop in my students an ability to solve problems, by using a process of thinking that would allow them to reason out what they knew.of the problem and then determine what they would need to know to solve it. In order to have either of these, the student would first have to develop some sort of sequencing skills. Since these are areas that go beyond simple discussion, it seemed reasonable to start out with an unknown laboratory exercise on the first day. I would be able to observe their skills in reading and following directions as well as their ability to manipulate the scientific equipment necessary for the lab. I could also ascertain from post lab discussion what kind of analytical skills they already had. Could they 16 determine a reason for the results and cite specific observations that showed this reason? The student obJectives (appendix C) were planned with the subsequent units in mind. The students would first have to be familiar with elements, ions and their symbols. They would need to know electron valence numbers to understand bonding. From there we would have to explore types of reactions, and see them taking place with inorganic molecules. Students would need to understand hydrogen ion concentration and how to test for it. They would need to know maJor types of organic compounds in their body and know how to test for each. as well as why and how each was important to their bodies. They would need to know the basic structure of DNA and RNA in order to understand how hereditary material was reproduced. First, we discussed matter in general, with the emphasis on the elements Important to the human body, especially carbon, hydrogen, oxygen and nitrogen. We then went on to the structure of atoms which led us to bonding. Now that we had molecules and their structure, we were ready to study chemical reactions, which took us to body metabolism and energy. The next logical topic seemed to be inorganic compounds, particularly acids, bases, salts and pH indicators. From there, we learned about maintaining the body’s 17 buffer system. Now, we were ready for organic compounds. The first organic compounds we covered were carbohydrates, and then we went on to lipids, proteins including enzymes, nucleic acids and adenosine triphosphate. The unit in previous years had only covered energy, structure of the atom and molecules, compounds, and motion of molecules (see appendix A for i986/87 outline and appendix B for 1988). On the first day of the unit, the students took a 49 question pre-test, 33 of the questions were multiple choice and the rest were short answer and essay. The students attempted to answer all of the questions, even though they would not be expected to know anything about some of the material. The students were weak in many areas, and showed little knowledge of chemistry. The students then began studying the chemistry chapter and related readings. The second day began with an overview of matter, with an introduction to the elements and their symbols. We then went on the third day to the structure of atoms. I try to make it very clear that our model of the structure of atoms is based only on indirect evidence, and to that end, began the introduction to our first chemistry lab, “The Atom Lab". (See Appendix J for lab activities.) We also began a write-up for a black box lab. 18 The fourth day, students are given a clay sphere with a small household item embedded somewhere within it. They must surmise a model of the “nucleus" after poking the “atom" five times with a probe. Each time the probe enters the "atom“ they must describe what, if anything, they encountered. When the first model is drawn they are allowed to take five more stabs, make a model and so on until they are very sure they know what is in the center. As their knowledge of the “nucleus“ expands, the model they draw changes and becomes more exact. They then write a conclusion telling why they think the “nucleus" Is what they state it is, based on the observations they made. It is an excellent time to stress the writing of conclusions because the steps are so simple to see. The "atom splitting“ ceremony is always a big draw with many oohs, ahs, and groans of disappointment. Some students of course, cheat and some guess correctly without cheating, but most have the problem of basing their guess on discovery of only part of the obJect, somewhat like the blind men who tried to describe an elephant by only touching one part. A discussion is scheduled the next day of why the identity of the hidden item was so difficult to predict, as well as how models are useful to further our understanding of things that we cannot see. We 19 also begin a discussion of bonding, using the Inaccurate but easy-to-see Bohr model of the atom. We then spend several days on reactions and the energy produced or used. The energy discussion takes us to diffusion and osmosis with demonstrations. By the middle of the second week, we are ready to start a learning compounds, pH, acids and bases. We spend a day on concepts, such as the blood buffer system, with lecture and discussion and then start to read and write laboratory exercises. On Friday of the second week, the students have their first review quiz. The third week is spent entirely on the acid/base related laboratory exercises. The students are given a group of labs, and proceed at their own pace with any lab they choose. This procedure cuts down on long lines for particular chemicals and waiting to use specialized equipment, although it is more hectic for the teacher. We finish the week with a discussion on conclusion writing and a short quiz on reactions and energy. Week number four finds us back to lecture and discussion of background material. We cover carbohydrates, lipids, proteins, enzymes: watch a couple of demonstrations on protein structure and denaturing; and begin writing protein lab exercises. A short quiz is given on Friday, as well as the opportunity to test some enzyme action in the lab. The 20 following Monday we start on nucleic acids. We do two exercises, one which requires the students to figure out the structure of DNA by assembling pieces of a DNA puzzle. The other one is done the following day and the students produce a three dimensional DNA structure that they can coll. We Ialso use rubber bands to demonstrate supercoillng. We start with enough bands knotted together to cross the room. It’s amazing how small a space one can coil rubber bands into. After spending two days on review, the students took the post-test. I start each unit by asking students to read the chapter to be covered. “Reading“ probably isn’t a good word to use, as I expect the students to do more than read. First, I ask them to skim the chapter by reading the things that are printed differently. and all the captions under graphs and pictures. They also need to look at the end of chapter questions so they can see what is most important to me as well as to the authors. The present text was chosen with this accond in mind. The second time through, I expect them to read from beginning to end. The third time through, they stop at the end of every section and close their eyes and try to remember what they Just read. If they can’t do that, then they are to go back and read the first paragraph of the chapter, close their eyes and recall. When they 21 have mastered that, then they again work on a section at a time. The last time through is another skim, this time finishing with the study outline at the end of the book. This process, if done correctly, should take them many days to complete. (I doubt however, if any but the best of my students actually do more than plow through from beginning to end, even though reading for meaning is a skill all should master to understand the significance of the written word.) The first day of a unit, we begin with an overview of the material. I tell them what they can expect time-wise as well as the work I will be expecting them to do. The textbook (Tortora and Anagnostakos, 1987) has an accompanying study guide, and selected material is assigned out of the guide during this time. I try to give them seven full days (over a *weekend) to prepare the material, because so many students are busy with after school activities. I then give the students a little background, and review of what has gone before. We have up to twenty minutes of lecture on days we aren’t in lab, and then throw the floor open to discussion. Of course, it does not always work as planned, sometimes we get sidetracked on discussion by Interesting questions brought up during the notes. In lecture, I cover the material that I consider to be the most important for them to learn, and the maJority of 22 the test questions will come from this material. During lecture, I use overheads (Appendix K) where appropriate, draw on the chalkboard, show specimens pertaining to the subJect and try to verbally draw as many analogies as I can. Demonstrations are an ever popular favorite. I also try to focus on examples of the material that will affect them directly. After a day or two of background, everyone seems to tire of talking, no matter who is doing it, so once the ground *work is laid, we begin to prepare for laboratory activities. If at all possible, I try to have at least two labs that focus on the material at hand, preferably those that approach the concept from different directions. Often, we have several labs on similar topics that the students can work on at their own pace as materials and equipment become available. Before the lab exercises, we discuss what we are trying to do, and then refocus direction during the lab. Often, the students will want to know “what will happen if....?“,“we’re finished with this, can we try to do....?" It often takes more time, but when that does happen, the students are truly learning. We try to have a post lab discussion on what happened and why to help the students with conclusions. Black box labs are pretty standard stuff in the science classroom, but our “atom lab“ is unique, as far 23 as I know. I think that this lab really shows how difficult exploring the unknown can be. It also lets them see what models and theories are all about. I have brought in new material developed by fellow teachers at summer workshops. (See Appendix J for specific laboratory exercises used in this unit.) This new material allows me to bring university techniques (which are often the techniques that modern science technology industry uses) to the high school. They learn what is being done in commercial labs around the country. The students especially enJoyed the labs we did on pH and indicators. we prepare many of the indicators and many of the things we test for pH from fresh fruits and vegetables. It is astounding to them that red cabbage Juice worked Just as well, if not better, than universal indicator to determine pH. They all brought lots of things from home to test for pH as well as indicators. Next time, however, I plan to use a blender and suction filtration -- no more mortar, pestle and gravity filtration. It slows the process up too much. At the beginning of the unit, most of my students are still apprehensive about using some of the equipment for lab activities. All the students are in at least their second year of high school science. I 24 was appalled when they all reached for a beaker instead of a graduated cylinder to measure larger amounts of liquids. Stop! Walt! Measure 150 milliliters of water using a beaker. Now, measure 150 milliliters of water using a graduated cylinder. Put the water from the cylinder into an identical beaker and notice the difference. Oh....! The light dawns -- at least for a little while. Next week we must go over the same thing. As they grow more familiar with accurate measuring, and more familiar with pipettes and cylinders, their lab results did improve, as did their lab skills. They are soon handling small amounts or large amounts of materials with all the equipment available. When experiments were done with blood later, not one of the students wanted to be shown how to use a capillary tube. They all knew from using pipettes. These students are comfortable using laboratory equipment and supplies after five weeks In the lab. Even unfamiliar procedures are quickly mastered because they draw on past experience with similar items. The students this year are more aware of what is going on, what they might expect to happen, than students in years past. For example, I always do a food analysis lab in early February. We spend days testing known materials for monosaccharides, proteins, amino acids, starches and fats. For a test, I give the students an 25 unknown - something that is available for them to test during the exercise, even if they don’t get around to it. In years past, students did not use time well, a lot of lab time was wasted in chatter or other delaying tactics, so not all substances got tested. When it came time for the unknown, many of the previous students did not even seem to know what the test they were using was testing for. Many tested for simple sugars using Blurets solution (a amino acid test) instead of Benedict’s solution (a test for simple sugars). After all, they are both blue, right? Needless to say, we did not have a high number of accurately identified unknowns. This year, each and every student identified the substance they were given, and amply supported that identification with observations from their testing. The only fault that I could find was that the students wanted to identify specific amino acids and simple sugars, and you Just can’t do that using the tests they had available, but they tried. Many even went back and tested the substance they thought they had as an unknown, Just to compare. I believe that this is a direct result of all the work we did in the chemistry section, both in lab and in lecture. To sweeten things even further, since the students know' what they are doing, instead of trying to follow poorly understood directions, there is 26 far less time wasted on trivial pursuits. When doing a lab, these students are on task most of the time. A maJor goal I have is to teach students to develop good observational skills and to use care in recording them. I also have the students use these observations to make conclusions so they can tell why something happened. “I think that this must have been what was going on because I saw these things happening. . . . . . . . . " These capabilities are not only important in the lab, but in life as well. Predicting what should happen is another skill that we work on . The first couple of lab exercises are designed to force observations and clear, logical thinking. It is also important that the students become familiar with various laboratory equipment and are comfortable, and precise, while using them. We do lots of measuring, and massing, and manipulating. The students learn the process of making extracts, doing dilutions, testing solutions for various components. We even borrowed a spectrophotometer so the students could use electronic equipment similar to what commercial labs are using. Pipettlng is a new technique for the students this year -- another way to stress accuracy. The students seem more comfortable with pipettes than with graduated cylinders. 27 In order to make lab exercises seem a little more special, I prepared a booklet to record data. Condensing the handouts (when there are any) is a good way to insure that the lab directions are at least read, if not studied, before we actually do the experiment. Using a lab book also eliminates all those scraps of papers that students always want to use to keep haphazard observations. (Sometimes I think they do that so the observations are easier to lose!) Most of the students are very careful and take pride in keeping their books neat. The booklet also organizes all their laboratory activities in one place, as well as enhances data recording and retrieving, so they can easily refer to previous work. Many take advantage of this. Evaluation Any evaluation instrument has limitations. The standard “chapter test" is the one most commonly used in the high school. However, it is impossible to present all the topics that were covered in a unit in Just one evaluation. The items on an obJective test must necessarily reflect the ones that the teacher thinks is most important for the students to know. Perhaps these topics will be significant in the students’ lives, or they vnil be necessary to understand the next unit, or they may reflect the personal bias of the teacher. When choosing from a bank of questions, the process ends up to be somewhat subJectlve, no matter how careful teachers are. A more difficult evaluation, and perhaps the way we should be grading our students, is performance of the daily tasks and laboratory work. Essay exams, while favoring those that are comfortable with words, gives a better idea of what the students are sifting out from the information we give to them. Essay tests are wonderful ways to see 28 29 inside the students mind, and are very easy to write, but so time-consuming to grade and almost impossible to grade obJectively enough to compare performance from one student to the next, or from one year to the next. That leaves us with the old stand by, multiple choice tests. Multiple choice tests are easily scored, analyzed and can be compared obJectively with one another. We must remember, however, that some students are much better than others at analyzing the teacher through the questions and can figure out the answer that the teacher wants. For my main evaluation instrument. I chose a multiple choice test supplemented with some short answer questions. I have a computerized data bank of test questions written by the author (or is it really the publisher?) of the text we use. I have added many of my own favorite questions, so there are quite a variety to choose from. After I had determined the obJectives for the unit, I went through the test bank and chose the questions that I thought would be especially important for my students to know. I made two different versions, one for the pre test and the other for the post test. There were 36 multiple choice questions, nine of which were not identical, but covered the same obJectives. In addition, there were eleven short answer, diagram and analysis questions to 30 cover material that would be difficult to answer adequately in the item choice format. (Appendix D) The first day of the unit, we began with a pretest. I explained that the obJect of the test was Just to determine how much they knew about the subJect, not to go in the grade book. During the unit we had several short quizzes to make sure the material was making sense to the students, and at the end of the unit, we had the other version of the multiple choice. short answer test. The post test was given again to the students in April to check retention, with no advance warning, so they were not able to study for it. The raw score data from the pretest was put into a standard score xxxz~x~9 c t Haggis”! J n S .m J t S n B S m N..” M t e cunr e H d H R U “ IBt m... . r K O D c J S M t L n 1+P t N t C S S O P 1m A a S m K .w H G Paints SOOTEd 36 On the retention test in April, (see Figure 4 for standardized T scores) three students were not available to take the test. One of the students scored high on both the pre and post test, and the other scored low on both. The third scored low on the pre test and above the mean on the post test. A student who had not taken the pretest was present for both the post and the retention test and that data is included. (appendix H) The mean of the April test was 28.9, the median was 32 and the standard deviation was 9.4. Thirteen of the students either did better than their original score or came within 3 points of their post test scores (see Figure 6). The scores were analyzed to determine correlation between the two tests. This correlation was 0.998, another high positive correlation. However, when a t test was done, the probability that the correlation was due to change turned out to be greater than 1096. In pure science. this would be unacceptable, but in education, where testing cannot be as exact, it isn’t enough to throw out the data. These similar scores tell me that the students are retaining this information over a long period of time, probably because they are using it in most of the units covered since then. I was pleasantly surprised to see so much retention over time. This retention convinces me that the unit has produced the 37 desired results, even though I can see no statistical differences from last year’s test scores. The end of the year grades has borne out my theory that a strong chemistry background enhances the study of physiology. In 1986 there were sixty-one students. Among those students were the five 4.0 students that shared valedictorian honors at graduation in 1989. We were using a simpler book, but the competition was stiff. That year, 18% of the students earned an A, 44% earned a B, 26% a C, 8% a D and 3% and E. In 1987, due to an increase in the number of science course offered (some of which were less difficult), the student numbers dropped to 23. Of that number, none received an A. 43% of the students earned a B as a semester grade, about the same percent as the previous year. There were 39% with C’s, up from the previous year. 8% earned 0’3 and 8% earned E’s, both percentages up somewhat, but the academic caliber of the students wasn’t as strong. This year, of the eighteen students who finished the class, 27% earned A, 33% earned B, 22% earned C, 5% earned either a D or an E. If we compare‘thls to the two previous years (Figure 7), 27% A’s is significantly higher than either previous year. There are as many A’s in the class as there are B’s, and more than there are C’s. The A students are probably on an academic 38 par with those of two years ago, but I consider the B students to be my shining glory. Many of these students are those who struggled, really worked hard, to get D’s and C’s in introductory biology. Physiology is a much more difficult class, due to both the subJect matter and the amount of work required. Some of the improvement is due to added maturity, of course, but I think the some of it comes from the basic understanding of chemistry needed to understand physiology. It would be interesting to find a way to find out exactly what caused the better grades in a "harder“ class. Figure 7, Three Year Grade Comparison of Chen Unit 50 7. g ‘0 5% . 7/.- 30 4%.: s . 7%”: 5 / é’ d 20 z" _ / 4555:: S /9' / ‘ t 10 ////’ 2g" / s I I ‘; / (60% 60-682 70-787. 80-892 90-1002 gr ade r ange .2 students in 1988 3E}, 2 students in 1987 .2 students in 1988 When I look at the item analysis of the tests (appendix I), there was a mean item difficulty of 63 on the pre test and a mean item difficulty of 34 on the post test. This is a decrease of 29%, due to increased knowledge of the material. An individual item analysis of the post test (appendix I) shows that item number 19 39 and item number 23 on the post test had a difficulty index of 95%. Only 2 or 3 students got them correct, and they aren’t the students who normally do well on tests. I think that these students chose that answer by chance rather than knowledge. The questions should be considered invalid. There was also one test item in which the answer key' was inadvertently scored incorrectly. These three items may have skewed the data analysis to show a higher item difficulty than there actually was. It does tell me that these items should. be reworked if they are to be included in another test because they are not discriminating the top ability students from the lower ability students. Analyzing the unstructured tasks of the students is a more complicated Job than analyzing tests. These students seem so much more sure of themselves in almost every aspect of the class work than previous students. Their analytical skills are better, they see correlations more quickly, they can more easily divide problems up into subunits and then synthesize the resulting information. They are more adept at using laboratory equipment, and quicker at figuring out how something unfamiliar should be used. Reflections In summary, the pre-physiology chemistry unit was expanded from one or two weeks to nearly six. More laboratory exercises were included, including some that were more complex than those presented in previous years. The extra time allowed the students to test and investigate beyond the original scope of the lab activities. It also allowed the students to hear, see and experience the concepts in several ways, many different times. The first labs built on their natural curiosity and presented common things in an uncommon light. Discrepancy provided for learning. Later labs built on their growing understanding of molecular reactions and provided visual evidence to back up the information gleaned from the text and the teacher. Laboratory notebooks taught neatness and organization. We have all heard that practice makes perfect, and that surely applies to learning as well. The students had access to more details about the chemical make-up and working of common body chemistry. These details 40 41 seemed to help their understanding of the topics covered. Imagine learning as a deep mine, with levels every few feet, corresponding to the amount of detail presented. I have always believed that students never go quite as deep in the mine as you would like to have them, and that their level of understanding is one or two levels above where you are teaching from. If we teach from the surface, they quickly decide that perhaps the topic isn’t all that important and very little is retained. If we dig quite deeply into a subJect, they follow and learn more than they would have with Just a surface presentation. This longer unit allowed us to dig deep enough into chemistry -- and thus physiology —- to understand what many things are doing at the molecular level. I think this five or six week unit is particularly strong in investigative and manipulative skills. These are lab based activities, at least to start with. It provides the student with an overview of chemistry in general as well as providing enough specifics to understand what is happening in their bodies on a molecular level. This unit is practiced enough and understood well, so the knowledge is retained for long periods of times. The students carried the information through to the next units instead of forgetting at the end of the chapter. The extra time we spent on the 42 chemistry unit allowed for the expansion of knowledge. This extra time was a drawback, however, when it came to the units covered the rest of the year. Even though the students have a much better sense of what is going on, something else had to be cut to make room for this unit. It is difficult to decide where to make the cuts. In 1986, a week was cut out of the circulatory system, the excretory system, and the end of year pig dissection. Another weakness is the testing method. The tests that I used weren’t complete enough in assessing what the students actually learned. The tests need to be revised. I would like to include an essay on problem solving and a section on writing conclusions from given observations. There should be a pre test for every unit as well as a post test. That might help me decide what could be cut another-year to make the time for chemistry. We could have used the extra week that I took from the cardiac section. I would like to add at least another week to the unit so I could encourage independent investigations using the present labs as a springboard. I see this unit as one that constantly evolves as we learn what works best to help with subsequent units. I also see it changing with the introduction of more sophisticated equipment in our laboratory and as the industrial technology changes. I think we need to have 43 a quicker trickle-down from industry and colleges than we have had in the past. People from these areas of science should be brought into the classroom to present some of the material. It seems to me that the longer time spent on chemistry has improved the physiology course in many ways. The students seem to retain information longer. The students find it easier to analyze and determine unknowns. The students are more at ease with the techniques and equipment of science. They understand better how their bodies work at the molecular level. They perceive more chemistry concepts to be important to their daily lives. The students learn first hand how scientists work. These are all skills that we want our students to learn when they do science, and the whole idea of physiology is to understand the human body’s homeostasis. It seems to me that increased time on chemistry, which covers all these areas, has served that purpose for these students. REFERENCES CONSULTED 44 REFERENCES CONSULTED Alexander, Bahret, Chaves, Courts, D’Alessio 3191291 1986 Siver Burdett, New Jersey Bartar, Moeller, Kleinberg, Guss, Castellion & Metz 1978 Academic Press, NY Blosser, Patricia E. "Labs -- Are They Really As Valuable As Teachers Think They Are“ May 88 NSTA Bryant, Richard J. & Marek, Edmund A. “They Like Lab-Centered Science“ Nov 87 NSTA Crager, Jean 6., Jantzen, Paul G. & Mariner, James L. 1985 Macmillan Publishing Company, NY Dressel, Paul & Nelson, Clarence “Questions and Problems in Science“ 1956 Cooperative Test Division, New Jersey Frazier, Richard "Beginning Without A Conclusion“ The_$cience_leachen. May 88 NSTA 45 Good, Thomas L. & Brophy, Jere E. 1980 Holt, Rinehart and Winston Hagerman, Howard H. Lectures on Statistical Analysis, unpublished NSF-MSU Behavioral/Environmental Workshop 1989 Hetherlngton, Martin “Scientific Literacy Can Be Achieved“ M1cbigan_fichQQL_BQand_lQunnai Apr 89 Hounshell, Paul B. “Labs Off Limits“ Apr 89 National Science Teachers Association Kilburn, Robert E. & Howell, Peter S. Exeiening_Life_Seien§e 1981 Allyn & Bacon, Boston Kraus, David C9n:ee&e_in_M9dern_Bigiggx 1984 Globe Book Company, NY Mahadeva, Madhu N. “From Misininterpretations to Myths’ Apr 89 NSTA McCormack, Alan J. & Yager, Robert E. “A New Taxonomy of Science Education" Feb 89 NSTA 46 Metcalfe, Williams & Castka W 1986 Holt, Rinehart, NY Morrison, Cornett, Tether & Gratz 1977 Holt, Rinehart & Winston, NY Otto, James H. & Towle, Albert M9dern.hicipgx 1985 Holt, Rinehart & Winston, NY Pizzini, Edward L., Abeil, Sandra K. & Shepardson, Danie “Rethinking Thinking in the Science Classroom" Dec 88 NSTA Rubin, Amram & Tamir, Pinchas “Meaningful Learning in the School Laboratory" November/December 88 NABT Slesnick, Balzer, McCormack, Newton, Rasmussen 1985 Scott, Foresman, Illinois Stryer, Lubert Bicchemistnx 1981 W.H. Freeman, San Fransisco Tinnesand, Michael & Chan, Alan "Step 1: Throw Out the Instructions" Sep 87 NSTA 47 Tortora, Gerard J. & Anagnostakos, Micholas P. Pr1nci21es_9f_AnaL9mx_and_Ehxsioiggx 1987 Harper & Row, NY Tortora, Gerard J. & Evans, Ronald L. Erincieies_gf_fluman_2hxsigiggx 1986 Harper & Row, NY Vacca. Richard 1981 Little, Browne and Co., Boston Vander, Arthur J. Sherman. James H.& Lucian. Dorothy S. Human_Ehxs19i9gxI_the_Mechanisms_91_figdx_£unctign 1980 McGraw-Hill, NY Wallace, Rober A.. King. Jack L. & Sanders, Gerald P. BiQicgx_;_The_Science_gf_Life 1981 ‘ Scott, Foresman, Ill. Weinreb, Eva Lurie Anatgmx_and_2hxsieiggx 1984 Addison-Wesley, Mass. Yager, Robert E. “Assess All Five Domains of Science“ Oct 87 NSTA BS§$_flandbggk BSCS Blue Version 1985 D.C. Heath. Mass. GLOSSARY acid active site ATP anabolism anion atom atomic number base (alkali) buffer carbohyrates catabolism catalyst cation colloids compound 48 GLOSSARY substance that produces hydrogen ions when dissolved in water place on an enzyme that binds its substrate adenosine triphosphate,molecule that provides short-term storage of energy in the cell, easily broken down to release that energy synthesis reaction , two or more substances combining to form new and larger molecule negatively charged ion smallest unit of structure entering into reactions the number of protons in an atom ions substance that produces hydroxyl when dissolved in water solution of chemical compounds capable of neutralizing both acids and bases, able to maintain an equilibrium pH organic compound with formula (CH20)n, sugars, starches, cellulose, chitin breaking bonds to form newer, smaller molecules to release energy substance that will change the rate of a chemical reaction without being changed in that reaction positively charged ion mixture of solvent and intermediate sized particles that are too small to settle out, but too large to dissolve a pure substance with two or more elements in a fixed ratio; consisting of a single molecule type covalent bond catabolism diffusion disaccharides DNA electron elements energy levels enzymes equation exchange rxn formula hydrogen bond indicator induced fit 49 interaction of elements in which pairs of electrons are shared to form a molecule breaking bonds to form newer, smaller molecules to release energy movement of molecules from an area of high concentration to an area of low concentration dimers of two simple sugars deoxyribose nucleic acid, contains all information needed to build or repair an organism negatively charged particle found outside the nucleus substances that cannot be broken into simpler ones by chemical means. It is a pure substance containing atoms of only one type areas around the nucleus where there is a large probability of finding electrons organic catalyst shorthand way of denoting a chemical reaction combination of synthesis and decomposition reactions; atoms being broken apart then each combining with another to form other molecules symbols that give ratio and number of elements present in a molecule or compound weak intermolecular electrostatic attraction between two polar molecules organic dye used to tell the pH of a substance theory to describe enzyme — substrate interaction inert inorganic ionic bond ionization isotope lipids lock and key mass number matter metabolism molecules monosaccharlde neutralization neutron nucleic acids nucleotide 50 without active chemical properties, not likely to react simple compounds that usually lack carbon atoms attraction of cation with an anion to form a molecule dissociation of ionically bonded molecules into their component ions when dissolved in water atom that has the same chemical properties but slightly different atomic mass caused by a difference in the number of neutrons type of organic molecule containing carbon, hydrogen and oxygen in no particular empirical ratio theory to describe the way an enzyme interacts with the substrate, no longer considered to be valid number of protons and neutrons found in an atom, also known as atomic mass anything that occupies space and has mass the sum of all anabolic and catabolic reactions in the body two or more atoms bonded together simple five or six carbon sugar reaction of an acid and base to form a salt and water neutral particle found in the nucleus found in the nucleus of the cell, made of simple five carbon sugars, nucleotides and phosphates purines or pyrimidines found in nucleic acids nucleus organic osmosis periodic table pH polysaccharide proteins proton radioisotopes reaction reversible rxn RNA salt saturated 51 area of atom that contains most of the mass molecules that contain long chains of carbon atoms bonded in a 1:2:1 ration to hydrogen and oxygen atoms movement of water molecules from an area of high water concentration to an area of low water concentration across a selectively permeable membrane arrangement of elements in chart form, based on their chemical characteristics an exponentially derived scale that indicates the relative concentration of hydrogen ions in a substance polymer of numerous simple sugars large, complex organic molecules with nitrogen, sulfer or phosphorous atoms as well as carbon, hydrogen and oxygen atoms positively charged particle found in the nucleus of an atom radioactive isotope, unstable, gives off some type of radiation the bonding or unbonding of molecules reaction in which the end product can revert to the original reacting substance ribonucleic acid, single stranded nucleic acid that has diverse functions in the production of proteins substance when dissolved in water will dissociate but not into hydrogen or hydroxyl ions lipids containing carbons singly bonded to each other and as many hydrogen atoms possible solute solution solvent substrate suspension symbols unsaturated valence number 52 smaller part of any mixture, usually was a solid before being dissolved liquid or gas in which another material has been dissolved larger part of a mixture, usually a liquid any substance involved in a reaction except the enzyme, can also be a protein or enzyme mixture of substances in which the particles are so large that they end up settling out of the solvent liquid one or two letter abbreviation for chemical elements lipids containing carbons with double or triple bonds to another carbon combining capacity of atom, usually related to the number of electrons in the outer shell. APPENDICES APPENDIX A TOPIC OUTLINE FOR PREVIOUS YEARS 53 I. Introduction to Chemistry (pre 1988/89) A. Element 1. Matter a. takes up space and has mass b. solid, liquid, gas 2. elements a. not decomposed into simpler substances by ordinary chemical means b. 106 - 92 natural, rest man-made 3. Letter abbreviations of elements a. H, C, O, N, Na, K, Fe, Ca, P 4. 26 in body a. 96% C, O, H, N b. 99% C, O, H, N, Ca and P c. 20 trace elements B. Structure of atoms 1. 2. 3. Smallest units of matter entering into chemical reactions Element has only one kind of atoms Nucleus a. center --> mass b. proton is +, neutron no charge c. nucleons a neutrons and protons Electrons, - charge a. move around nucleus b. = to t of protons c. atom is neutral Atomic # = # protons Atomic mass = protons + neutrons a. H has 1 proton b. He has 2 protons and 2 neutrons C. Atoms and molecules 1. 2. Chemical reaction a. atoms combining or breaking apart b. foundation of life processes Energy levels a. two in first b. eight in second c. simple molecules have 8 in third, more complex have up 18 d. filled shells are best, so atoms without filled shells tend to combine e. valence (combining capacity 1) extra or deficient electrons in outer shell 2) Cl (7 valence electrons) and Na (1 valence electron) 54 3) inert elements have filled outer shell 3. Combine in reactions to form molecules a. same kind of atoms --> multiatomic elements b. different kinds of atom -->-compound c. held by bonds which are attractive forces D. Ionic Bonds 1. electrons gained or lost = ion a. electron donor gives up an electron and has a positive charge b. electron acceptor takes and electron and has a negative charge c. positive and a negative Join (opposites attract) to form ionic bond d. less that half filled outer shells will lose electrons --> positive cations e. more than half filled outer shells will gain electrons --> negative anions E. Covalent bonds 1. Shared electrons 2. Single bond = one shared pair 3. Double bond two shared pairs 4. Triple bond = three shared pairs 5. same or different kind of atoms F. Hydrogen bonds 1. Covalently bonded to N or 0 but attracted to another N or O 2. will not make molecules but makes bridges in or between molecules 3. formed and broken easily 4. many bonds make a molecule more stable II. Radio isotopes A. Isotope - atoms chemically alike but with different nuclear mass from extra neutrons B. radioisotopes are unstable and decay by emitting radiation to reach a more stable state III. Chemical reactions (same atoms rearranged) A. Synthesis (anabolism) 1. two or more atoms, ions or molecules forming new, larger molecules 2. reactant + reactant --> product 3. 2N + 3 H2 ——> 2mg B. Decomposition (catabOIIsm) . 1. Breaks molecules down into smaller parts 2. Bonds are broken 55 3. reactant --> product + product 4. CH4 -"'> C + 2H2 C. Exchange ( syn. & decomp.) 1. AB + CD --> AC + 80 or AD + CB D. Reversible 1. reaction will go in either direction 2. some need special conditions E. Metabolism 1. all syn. and decomp. rxns in body 2. High = faster than normal, eat w/o weight gain, high energy level 3. low = slower than normal, lethargic, weight gain, slow healing F. Collision Theory 1. constant movement of atoms or molecules 2. collide with each other 3. energy transferred can disrupt electron structure to make or break bonds 4 Factors a. velocity of particles b. energy of particles c. specific configuration of particles d. orientation of particles 5. Activation energy - is amount needed to disrupt a stable electron arrangement G. Energy and reactions 1. E = capacity to do work a. potential b. kinetic . Chemical ~energy released when breaking bonds and absorbed when forming bonds Mechanical- energy of motion Radiant - heat and light in waves Electrical - flow of charges or ions . Energy can be transformed from one type to another, but not created nor destroyed IV. Chemical composition and life processes A. Inorganic compounds 1. Most w/o C 2. Vital to body functions 3. Water - most important and abundant (60% of RBCs, 75% of muscle tissue, 92% of plasma) a. solvent and suspensory medium 1) solute in solvent = solution, will not settle out 2) particles in solvent = suspension, will eventually settle out b. participant in many reactions c. moderates heat changes mouse) N 4. 5. 6. d. e. 56 cools body acts as lubricant Acids, bases and salts a. b. dissociate in water called elctrolytes, will conduct current acid --> hydrogen ions plus negative anion base --> hydroxyl ions plus positive cations salt --> anion and cation 1) acid + base -> water + salt 2) ions of salts in body are essential elements Acid/Base balance (pH) a. b. C. d. e. more hydrogen ions; the more acid more hydroxyl ions: the more basic (alkaline) pH describes degree of acidity or alkalinity scale from 0 - 14 1) number of hydrogen ions in solution in moles per liter 2) PH 7 = 10'7 M/L, equal hydrogen and hydroxyl ions 3) pH 4 = 10-4 M/L 4) pH 10 = 10‘10M/L mole 1) mass in grams of combined atomic mass of substance 2) contains 6.023 x 1023 atoms Maintaining pH: buffer systems a. b. C. normal limits are narrow .buffer system maintains balance within limits 1) reacts with strong acids and bases and replaces with weak acids and bases 2) strong substances dissociate easily and add many ions to the system 3) weak substance do not dissociate well Carbonic acid/bicarbonate buffer 1) weak acid (carbonic acid) and weak base (sodium bicarbonate) 2) if strong acid is added to system, weak base will react to form salt and weak acid a) HCl + Na2C03 -> NaCl + HzC03 V. 57 3) if strong base is added, weak acid will react to form water and weak base a) NaOH + H2C03 -> H20 + NaHC03 4) extra water and salt removed by kidneys Organic compounds A. Contain chains of carbon 1. AND“) react with other molecules to form larger molecules do not dissolve easily in water Large sizes for body structures covalently bonded and decompose easily (ionic bonds break down easier, but reform very quickly) B. Carbohydrates (sugars and starches) 1. structural units in DNA 2. converted to proteins or fats for energy 3. readily available source of energy for life 4. food reserve as glycogen 5. monosaccharide - 3 to 7 C’s 6. proportions (CH20)x 7. disaccharides - 2 or more mono’s a. Joined by dehydration b. water soluble c. broken down by hydrolysis, sweet taste d. sugars 8. polysaccharides - many Joined units a. broken down by hydrolysis, but no sweet taste b. usually not water soluble c. starches C. Lipids 1. Combinations of C, H. and O 2. dissolve in solvents like alcohol and ether, but not water 3. made of 3 fatty acids and a glycerol by dehydration synthesis a. saturated, no double bonds, animal fat b. unsaturated, some double bonds, vegetable oil 4. Highest concentrated form of energy (twice that of sugars or proteins), but is 10-12% less effective 5. phospholipids 6. steroids 7. carotenes D. E. F. 58 8. prostoglandins (PG) a. membrane associated b. influence function of cell c. produced by cell membranes d. mimics hormones e. modulates hormone reactions Proteins 1. make body structures 2. related to many physiological functions 3. always C,H,O, & N, may contain S & P 4. made of amino acid chains a. combined by dehydration b. bonds called peptide bonds c. only 20 amino acids used 5. Complex structural organization a. primary - sequence of amino acids b. secondary - coiling in 2 dimensions c. tertiary - folding into 3D shapes d. quaternary - several tertiary bonded Nucleic Acids 1. 2. DNA & RNA made of units called nucleotides a. Nitrogen bases: rings 1) adenine: purine double ring 2) guanine: purine double ring 3) thymine: pyrimidine single ring 4) cytosine: pyrimidine b. Pentose sugar c. Phosphate group Model 1953 by Watson, Crick and Wilson Characteristics of DNA a. 2 strands with crossbars b. twists into double helix c. uprights are alternating sugars and phosphates d. rungs are paired bases, pyrimidine with a purine e. deoxyribose sugar Genes are segments of the DNA molecule a. determine traits b. control cell activities RNA a. single strand b. thymine replace by uracil c. ribose pentose sugar d. messenger, transfer and ribosomal varieties Adenosine Triphosphate (ATP) 1. Short term storage of energy for cellular activities 59 2. 3 phosphate groups, adenine and a ribose sugar 3. one phosphate broken off by hydrolysis to give energy APPENDIX B UNIT OUTLINE FOR 1988/89 THE CHEMICAL LEVEL OF ORGANIZATION I. 60 Introduction (1988/89) A. In general 1. Matter a. anything that occupies space and has mass b. made up of building units called chemical elements 1) can’t be broken down into simpler substances by ordinary chemical reactions 2) composed of atoms all of the same type 3) 106 elements: 92 occur naturally 4) symbols a) one or two letter abbreviation from either Latin or English name b) MUST know i) H - hydrogen (usually in water) ii) C - carbon (backbone of other compounds) iii) 0 - oxygen in water) iv) N — nitrogen v) Na- sodium vi) K - potassium (usually 4) vii) Fe- iron viii)Ca- calcium ix) Mg- magnesium x) 01- chlorine xi) He- helium xii) S - sulfer xiii)Cu- copper xiv) Zn- zinc xv) P - phosphorous c) subscript gives atomic number d) superscript gives mass ~26 elements in human body a) 02, C, H2, & N2 = 96% Of body weight b) with Ca and P = 99% body weight c) other trace chemicals 1) K, S, Na, Cl, Mg ii) Fe, I, Cu, 2n, Mn, Co, Cr, Se, Mo, F, Sn, Si, V, B d) refer to p 34, exhibit 2-2, Tortora B. C. 61 Structure of atoms 1. smallest unit of matter entering into reactions a. size range from 1.0 x 10'8cm to 5.0 x 10‘3cm b. 50 million of largest end to end would be ~2.5cm most of atomic mass 2. Parts a. nucleus 1) 2) 3) 4) 5) protons - + charged particles (1 amu) neutrons - neutrally charged particles (1 amu) ends up with net positive charge P and N together called nucleons b. electrons 1) 2) 3) negatively charged particles that move around nucleus so rapidly they form a cloud in element, # electrons = # protons, so atom has no net charge 1/1836 of proton mass, therefore mass = 0 3. Differences in elements is number of protons in atom a. atomic number = # P b. atomic weight # P + N Atoms and molecules 1. Chemical reaction occurs when atoms combine or break away from one another 2. Electrons reactions actively participate in 3. Energy levels a. areas around nucleus where electrons are likely to be found b. each level has a maximum number of electrons it can hold I) 2) 3) 4) level one holds max. of two electrons and is closest to nucleus level two holds 8 electrons level three a) atoms that have an atomic weight of less than 20 can hold maximum of 8 electrons b) atoms that are more complex can hold up to eighteen electrons inner levels held very tightly 4. Outer compl 5. Vaien a. b. C. 6. Mole a. b. c. 7. comp a. 62 5) outer levels held less tightly energy level is more stable when etely filled ce (combining capacity) # of extra or deficient electrons in outermost energy level inert element has the outer level filled atoms with incomplete energy level tend to combine with other atoms by trading or sharing 1) if outer level is less than half full, the atom tends to lose electrons when combining a) form positive charged ion called CATION b) Na has 1 electron in outer level and less energy is used to lose electron than to "find" 7 others 2) if outer level is more than half full, the atom tends to gain electrons when combining a) forms negative charged ion called ANION b) Cl has 7 electrons in the outer shell and takes less energy to gain an electron than lose 7 3) if outer level is half full, the atom tends to share electrons when combining, but can gain or lose electrons cule two or more atoms combined with chemical reaction two of the same kind of atoms or two different kinds of atoms held together by chemical bonds ound substance that can be broken down into two or more other substances by chemical means 1) chemical changes involving sharing or transferring electrons must have at least two elements involved always bond in specific amounts that will not vary 8. 63 Formulas a. symbols b. coefficients indicate the number of molecules c. subscript tells number of atoms d. gives the ratio and number of elements present e. two types of formula 1) molecular a) gives number of molecules b) CH4 2) structural a) tells the way molecules are put together b) H l H—---C----H I H D. Ionic bonds 1. 2. Ion - atom that has gained or lost 1 or more electrons a. if gains electrons - ends up with negative charge - called electron acceptor b. if loses electrons - ends up with positive charge - called electron donor c. written with a + or — sign after the symbol Ions have a net neg. or net pos. charge. a. + and - attracts atoms together b. bond results c. bond is broken when compound is dissolved in water 1) ions move around in solution 2) even water ionizes to a small degree into H+ and OH" E. Covalent bond 1. 2. 3. Common in organisms, more stable than ionic Two or more atoms share electrons so each has a filled outer shell Electrons circle the nuclei of all atoms, spending an equal amount of time around each Single bond — one pair of electrons are shared, designated with single horizontal line 64 5. Double bond - two pairs of electrons are shared, shown by two parallel horizontal lines 6. Triple bond - three pairs of electrons are shared, shown by three parallel horizontal lines. F. Hydrogen Bonds 1. A hydrogen atom covalently bonded to one oxygen atom or one nitrogen atom, but attracted to another oxygen or nitrogen atom . Weak bond (5% of covalent) so will not bind molecules together Serve as bridges between molecules or parts of same molecules Easily formed and broken . Even though weak, several hundred in one molecule can add a lot of strength and stability G. Radioisotopes 1. Isotope a. atom that has the same chemical properties, but a slightly different atomic weight than another b. caused from have a different number of neutrons in the nucleus - all have the same 4 of P c. atomic weight on periodic table is an average of all the isotopes d. examples of hydrogen isotopes 1) protium 181 2) deuterium H2 3) tritium 18 2. Radioisotopes a. stable isotopes do not emit radiation b. some isotopes are unstable - they "decay“ (change nuclear structure) to a more stable form c. during decay they emit radiation that can be detected by instruments 1) instruments can estimate amount of radioisotope in a sample of material and form and image of distribution. d. nuclear medicine 01wa 65 1) radioisotope scanning a) doctors inJect radioactive isotope, such as 329, into patient b) n te where isotopes gather c) P used to treat leukemia d) 59Fe used to study RBC production 2) Positron emission tomography (PET) a) short-lived radioisotopes (11C, 13N, 15O) are produced and [put into a sol’n that can be inJected into the body b) as they circulate through the body they emit + charged electrons call positrons c) positrons collide with - electrons in body tissues, causing their destruction d) electrons release gamma rays as they are destroyed e) gamma rays are detected by PET receptors f) computers construct a picture that shows where the radioisotopes are being used in the body 9) show the effects of drugs in body organs, measure blood flow through organs, detect cancers etc. H. Chemical reactions 1. 2. equations are a shorthand way to describe chemical rxn Certain conditions must be present in body for rxn to occur a. temperature b. pH c. enzymes present synthesis reactions - anabolism a. 2 or more atoms, ions or molecules combine to form new and larger molecules b. A + B ----> AB combining substances are called reactants new substance is called product arrow indicates direction in which the reaction is proceeding . ex. N + 3H —--> NH3 (ammonia) 0 (DO. '14 g. h. 66 ex. in body, glucose combines to form glycogen and amino acids combine to form proteins often syn rxn is dehydration rxn when water is given off as a product 4. Decomposition reactions - catabolism . bonds of large molecule are broken and smaller molecules, atoms or ions are produced. AB --—> A + B 8X. CH4 ---> C + 4H ex. in body, digestion and oxidation of food molecules often a hydrolysis rxn where water is a reactant that is used up 5. Exchange reactions a. b. partly synthesis and partly decomposition AB + CD ---> AD + BC or AC + BD 6. Reversible reactions a. b. c. the end product can revert to the original combining molecules A + B <====> AB can occur because neither the reactants nor the end products are stable or under special conditions 1) special conditions are written under or over the arrows 2) special conditions can be heat or addition of water 7. Metabolism a. b. C. The body must break down molecules in small steps so the energy released does not destroy the body The sum of all the synthesis and decompostion reaction in the body. High metabolism means that the reactions are occurring at a faster rate than normal and body can’t always store it 1) tend to eat a lot without gaining weight 2) generate a lot of heat so often say they are hot Low metabolism means that the body reactions are taking place at a slower rate than usual 1) food is only partially broken down, and it occurs quite slowly 2) often have little energy, gain weight and feel cold 67 8. How chemical reactions occur a. collision theory 1) 2) 3) all atoms, ions, and molecules are always moving and colliding with each other. energy transferred by the particles in the collision might disrupt their electron structures enough so that chemical bonds are broken and/or formed factors a) velocities of particles b) energy of particles c) specific chemical configuration d) certain energy needed to disrupt bonds e) particles must be in particular orientation to react. b. Catalyst usually will be present 1) will alter rate of reaction without itself being affected 9. Energy and chemical reactions a. energy - the capacity to do work 1) potential - stored 2) kinetic - motion b. forms 1) chemical energy released during 2) 3) 4) breaking of chemical bonds and absorbed during the formation of bonds. a) building processes of body are synthesis reactions which use energy b) digestion is decomposition reactions which release energy mechanical energy is energy involved in moving (when the muscles move a part of the body) Radiant energy, such as heat and light a) travels in waves b) some release during decomposition reactions electrical energy from flow of charges, electrons or ions (essential for nerve impulses) 68 c. forms of energy can be changed from one to another, but never created or destroyed 11. Chemical compounds and life processes A. Inorganic compounds - usually lack carbon 1. Water (cannot live without more than a few days) a. most abundant and important inorganic substance in body 1) 60% of RBC. 92% of blood 2) 75% of muscle tissue b. excellent solvent and suspending medium (no chemical change required, amounts involved can vary) 1) solution - liquid or gas, the solvent, in which some other material. the solute, (solid, liquid or gas) has been dissolved a) can have more than one solute (or solvent) b) solute recovered by chemical means or evaporation c) example - salt and water 2) suspension - material mixed with the suspending medium will eventually settle out. a) example - cornstarch and water 3) colloids a) particles too large to dissolve b) too small for suspension c) change easily from liquid to semi-solid and back d) gelatin is good example 4) essential to survival a) blood in solution with oxygen/C02 b) carries dissolved nutrients c) suspend molecules to bring them in contact with other materials c. participates in chemical reactions, both synthesis and decomposition d. absorbs and releases heat slowly to moderate temperature fluctuations in body e. good cooling mechanism because when it evaporates, it takes large quantities of heat with it 69 f. serves as a lubricant - chest, Joints, digestive tract 9. is a stable element, it takes large amounts of energy to decompose it h. ionizes to be used in chemical reactions 2. Acids, bases and salts a. ionization 1) b. acid 1) 2) 3) c. base 1) 2) 3) 4) d. salt 1) 2) 3) when molecules of inorganic acid, bases or salts are dissolved in water, they dissociate into ions a) also called electrolytes because they can conduct electric current a substance that dissociates into one or more hydrogen ions (HT) and one or more anions. also defined as a proton (HT) donor because it provides hydrogen ions to the solution examples--vlnegar and lemon Juice (alkali) dissociates into one or more hydroxyl ions (OH‘) and one or more cations viewed as a proton acceptor because it removes hydrogen ions from the solution feels slippery because it removes the top layer of skin examples — ammonia and most detergents when dissolved in water, dissociated into cations and anions, but neither is (H+) or (OH') formed from reactions of acid with base (water is other product) This is called neutralization a) KOH +HCl -> HOH + KCl b) 2 KOH + H2804 -> 2 HOH + K280 many found in the body and are essential 70 3. Acid-base balance: the concept of pH a. f. explanation - in water, acids dissociate into hydrogen ions and bases dissociate into hydroxyl ions the more HT in solution, the more acid the solution the more OH' in solution, the more basic the solution . equal amounts of H+ and OH‘ mean the solution in neutral acidity expressed on pH scale that runs from 0 - 14 1) based on the number of H+ ions in solution expressed in moles/liter 2) at pH 7 there is 0.0000001 moles/L of H+ a) when this is written in exponential form 1 x10'7 b) convert the exponential number to positive and it is the pH number c) 1 x 10‘4 M solution of H+ is pH 4 3) a change of one pH number represents a 10 fold increase or decrease in the concentration of hydrogen ions 4) refer to exhibit 2—3 on page 36 of Tortora Neutral [OH‘] = [HT] 4. Maintaining the pH: buffer systems a. b. pH of body fluids may vary but range for each are specific and narrow buffer system reacts with strong acids and bases and replace them with weak acids and bases that won’t change pH values very much . most common is carbonic acid—bicarbonate buffer system 1) acid component HZC)3 <---> HT + HCOa- 2) base component NaHCO3 <---> ”6+ + HC03- 3) if strong acid is introduced, the weak base is activated a) HCl + NaHCOa <---> NaCl + H2C03 b) forms a weak acid and table salt 4) 5) 6) 71 if strong base is introduced, the weak acid is activated a) NaOH + Hzco3 <—--> H20 + NaHCO b) orms water and a weak base whenever buffering occurs, the concentration of one member of the pair is increased while the other is decreased The buffer substances (HCl and NaOH) are removed at the kidneys, and the buffer solutions are ready for reuse 5. Indicators a. pH scale 1) 2) 3) indicate degree of [ion] in solution most acidic (0) to most alkaline (14) 7 = neutral b. measuring pH 1) 2) 3) 4) electronic pH meter pH paper a) turns different colors at different pH i) mixture of chemical indicators ii) matched to color chart to find pH litmus a) indicates acid or base only b) pink 2 acid, blue = base c) can be liquid or on paper phenolphthalein turns pink in bases over pH 8 B. Organic compounds 1. In general a. made of long chains of carbon molecules 1) 2) 3) carbon can form four bonds with other atoms a) has four electrons in outer shell b) especially reactive with hydrogen relatively large do not dissolve easily in water 72 b. other common elements 1) hydrogen - one bond (1 electron in outer shell) 2) oxygen - two bonds (6 electrons “ " " ) 3) nitrogen - three bonds (5 “ ) 4) sulfur - two bonds (6 electrons in outer shell) 5) phosphorous - five bonds (5 electrons) c. useful for building body structures d. usually held together with covalent bonds 1) good source of energy 2) ionic bonds not good for energy because they form new ionic bonds as soon as the old ones are broken 2. Carbohydrates made by plants a. sugars and starches b. functions 1) building block of DNA 2) converted to proteins or fats 3) food reserves (glycogen) 4) most important is ready source of energy c. components 1) carbon, hydrogen and oxygen 2) ratio H:O is 2:1 3) general formula (CHZO)n a) glucose CC 3H1 06 b) ribose BAG 8 C) sucrose C12 22 12 d. groups, based on size 1) Monosaccharides - simple sugars made from three to seven carbons ( CSHI ) oare trioses b) 4 are tetroses c) 5 are pentoses d) 6 are hexoses ) moat important in body e) 7 are heptoses f) isomers can have the same number of carbons and be called by different names because the arrangements of atoms in the molecule determine its properties vii) sweet taste, soluble in water 73 2) disaccharides - two monosaccharides Joined chemically (C123220 a) formation is a dehydration synthesis - water is a product 3631206 + C631206 '> C12322011 + 2b) can be broken down by hydrolysis which uses a water molecule c) sweet taste, soluble in water 3) polysaccharides - several monosaccharides Joined [(C H1005)x I a§m dehydration synthesis to form b) hydrolysis to break down c) do not have a sweet taste d) not usually soluble in water e) storage form 1) starch in plants (white of potato) ii) cellulose in plants (strings in celery) iii) glycogen in animals 3. Lipids (essential for cell membrane) a. b. C. d. used for long term storage of food, release the most energy when oxidized composed of CHO but H:O ratio are not 2:1 insoluble in water, but should dissolve in alcohol, chloroform and ether examples of types - fats, phospholipids. steroids. and vitamins E and K (see exhibit 2-4, p 39, Tortora) e. molecule of fat is made up of a f. glycerol and 3 fatty acid molecules (dehydration synthesis) saturated fat 1) no double bonds between any carbons and all C’s are bonded to the maximum number of hydrogens 2) occur mostly in animal foods 3) also in cocoa and palm butters 4) many times are solid (nearly) at room temperature 74 g. unsaturated fat 1) one or more double covalent bonds between carbon 2) olive or peanut oil 3) quite often a liquid at room temperature h. poly unsaturated fat 1) two or more (many) double covalent bonds between carbons 2) corn oil, sunflower oil, soybean oil 3) usually liquid at room temperature 1. most highly concentrated form of energy 1) twice as much energy as proteins or CH0 2) but 10-12% less efficient as fuels than CHO J. prostaglandins (PG) associated with membranes and influence functioning of the cell by mimicking hormones k. lipo-proteins 1) HDL - remove cholesterol from blood so it can be excreted 2) LDL - seems to deposit cholesterol on artery linings 4. Proteins a. in general 1) complex 2) much of body structure and related to many physiological activities 3) denatured by change in temperature or pH (changes shape) 4) specific sequence of amino acids b. components 1) C, H. O 8 N: sometimes S & P 2) built of 20 different amino acids Joined with peptide bonds (dehydration synthesis) 3) 2 a.a. = dipeptide 4) 3 a.a. = tripeptide 5) 4 to several hundred = polypeptide 75 c. structure 1) 2) 3) 4) 5. Enzymes primary level a) sequence of amino acids in molecule b) single substitution can result in a deformation of molecule (Hb) secondary level a) coiling or zig-zag arrangement along two dimensions b) spirals or pleated sheets tertiary level a) bending or folding into a 3-D shape quaternary structure a) two or more tertiary patterns bonded to each other a. characteristics 1) a) 2) 3) 4) 5) organic catalyst which changes the rate of the reaction without being involved in the reaction can speed reaction up to 10 billion times without an increase in temperature or pressure which can kill the cell large protein molecules with characteristic 3-D shape specific in reactions catalzyed and molecules (substrate) reacting a) lock and key model b) induced fit 1) slightly plastic active site ii) can mold around substrate that "almost“ fits end in suffix “-ase” shape is important in determining activity a) altered by heat i) most won’t function above 60°C 11) high heat kills enzymes needed for life 6) 7) 8) 9) 76 b) lead and mercury compounds affect active sites of some enzymes 1) Pb and Hg poisonous ii) Hg absorbed through skin iii) Pb ingested or inhaled needed only in small quantities a) can be reused b) one molecule of catalase can catalyze the breakdown of 5 million molecules of H202 within one minute enter into reaction with substrate to form temporary complex Have an active site where the substrate can bind actions are reversible a) A + B--> AB can also be AB --> A + B b) usually written with double arrow 10) rates vary with environmental conditions a) temperature 1) rate increases until optimum is reached then is denatured and stops working ii) denaturization starts about 40 C (104F) and rxn rate drops sharply b) amount of enzyme and substrate i) rate increases until all enzymes are actively engaged and then it levels off c) pH i) optimum pH varies with enzyme ii) many at around 7 but there are exceptions such as pepsin which works best about 2 6. 77 b. Parts 1) some are only proteins 2) most have protein component called apoenzyme that is inactive without a non-protein cofactor -- whole thing called holoenzyme a) metal ions such as zinc, iron and calcium b) vitamins, especially the B vitamins c. mechanism of action 1) surface of substrate makes contact with specific region on surface of enzyme molecule known as active site 2) temporary intermediate forms called enzyme-substrate complex 3) substrate is transformed a) by rearrangement of existing atoms b) by breakdown of substrate molecule c) by combination of several substrate molecules 4) transformed substrate molecules = product 5) product moves away from enzyme 6) enzyme attaches to new substrate Nucleic acids: DNA (from parent to offspring) and RNA (from nucleus to cytoplasm) a. first discovered in nucleus of cells b. large organic molecules with C, H, O, N & P c. basic building unit is nucleotide (basic pH) 1) one of four possible nitrogen bases in a ring arrangement a) A and G are double ring purines b) T and C are single ring pyrimidines 2) pentose sugar called deoxyribose in DNA and ribose in RNA 3) phosphate groups 4) named according to nitrogen base d. structure deduced in 1953 by James Watson and Frances Crick from x-ray diffraction studies done by Roselyn Franklin and Maurice Wilkins e. 78 characteristics of DNA 1) 2) 3) 4) 5) two strands with crossbars strands twist around each other in double helix, most to the right sides of strands are made up of alternating phosphates and sugar crossbars are paired nitrogen bases - a large purine paired with a smaller pyrimidine, A-T and G-C genes a) hereditary material found in cells b) made up of segments of DNA molecules c) determine traits we inherit d) control all cell activities 7. Adenosine Triphosphate (ATP) found in all living systems and stores energy for cellular activities three phosphate groups and adenosine unit with adenine and ribose when terminal phosphate group is hydrolyzed the reaction liberated a great deal of energy a. b. C. f. . energy is used by cell for its activities left over molecule is ADP which can be bond another P if energy is added from decomposition reactions ATP <---> ADP + P + energy APPENDIX C BEHAVIORAL OBJECTIVES FOR CHEMISTRY UNIT (flbQNH 0\ 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 79 BEHAVIORAL OBJECTIVES FOR CHEMISTRY UNIT define matter, elements, atoms given symbohs of 15 selected elements, give names and vice versa list 4 maJor element and 12 of 20 trace elements in body explain simple Bohr model of atom: list parts and define each recognize elements from atomic drawing; sketch any element when given either atomic mass or atomic number calculate atomic mass from atomic number, electron number, proton or neutron number define and describe electron energy levels: given an electron number, be able to assign to the correct energy level predict atomic bonding relative to the number of electrons in the outer shell and/or position of the element on the periodic table define and give examples of molecule, compound, ionic, covalent and hydrogen bonding discuss importance of hydrogen bonding relative to human body define and discuss importance of radioisotopes in detection of homeostasis breakdown. discuss and give examples of types of chemical reactions: be able to recognize type of reaction from an equation list and explain 4 of 5 factors that affect the rate of reaction describe 3 of 4 forms of energy: given examples, tell form of energy involved List 4 of 6 important characteristics of water. be able to explain and give examples of each define and give examples of acids, bases, salts and pH. describe what makes a solution acidic or basic and how to test for acidity: derivation of most indicators given molarltv. [W], or [OH‘J determine pH and vice versa explain the properties of a buffer, and describe how the carbonic acid/ bicarbonate buffer system works in the body. define and recognize an organic molecule by name or formula: define list characteristics of carbohydrates, proteins, lipids, nucleic acids describe a simple chemical test for the three maJor types of organic molecules 23. 24. 25. 26. 80 given model parts of a DNA molecule, recognize that there is only one way to assemble: list bases and pairing order; draw simplified DNA or RNA molecule explain briefly how energy is stored and released in the body. interpret graphed or tabulated data write conclusions from observations, citing the observations for support APPENDIX D TESTING INSTRUMENTS 81 PHYSIOLOGY PRE-TEST FOR CHEMISTRY Fall 1988 Name Date Hour Read tail of the following questions carefully and answer them according to the instructions provided. MULTIPLE CHOICE: Select the lettered choice that best answers each question. 1. Chemically, the protoplasm of cells consists of a) mostly rare elements b) hundreds of different elements c) elements, each of which usually retains its own elemental characteristics d) mostly common elements e) mostly elements with high atomic masses The four most common elements in the human body are a) carbon, hydrogen, oxygen and chlorine b) carbon, oxygen, nitrogen, and chlorine c) carbon, hydrogen, nitrogen and calcium d) carbon, hydrogen, oxygen and iron e) carbon, oxygen, hydrogen and nitrogen Which of the following statements regarding pH is true? a) a dilute solution of almost any acid will have a pH of somewhere above 7 b) the pH scale is used to indicate the acidity of solutions, but not the alkalinity c) a solution of pH 4 is twice as acidic as one with pH 2 d) a solution with ph 8 is more acid (less alkaline) than one with pH 9 e) none of the above is true A molecule of carbohydrate contains the chemical elements a) nitrogen, carbon and hydrogen b) calcium, carbon and chlorine c) carbon, hydrogen and oxygen d) carbon, oxygen and phosphorus e) carbon, oxygen and nitrogen 10. 11. 82 C6H 206 a) Is an example of a structural formula b) represents a hexose c) is a form of glycerol d) is a product of the digestion of proteins e) is formed by the digestion of fatty acids Polysaccharides a) are a type of complex carbohydrate b) include lecithin c) are reduced to fatty acid on digestion d) contain nitrogen e) have a definite empirical formula A molecule of fat a) may be stored as part of a protein molecule b) is known as a “protein saver“ c) is converted into amino acids d) can repair or replace protoplasm e) is composed of one molecule of glycerol and three molecules of fatty acid The most complex organic compounds are a) disaccharides b) starches c) proteins d) fats e) monosaccharides Which of the following is true a) both adenine and DNA are found in the cytoplasm of the cell b) neither adenine nor DNA are found in the nucleoplasm of a cell c) DNA constitutes a part of the adenine molecule d) adenine constitutes part of the DNA molecule e) adenine and DNA are completely unrelated Genetic information for cell use is replicated from deoxyribonucleic acid into another type of nucleic acid a) called amino acid b) found only in the nuclei of cells c) having a more complex molecular structure that DNA d) after DNA has passed from the nucleus to the cytoplasm e) known as ribonucleic acid (RNA) The expenditure and transformation of energy which is the basis for all life processes a),is called anabolism b) is also the basis for organic evolution c) depends upon plant and animal hormones d) is controlled by chemicals called enzymes e) may be related mathematically using the Hardy-Weinberg law 12. 13. 14. 15. 16. 17. 18. 19. 20. 83 A substrate a) is a substance that is affected by a vitamin b) is the substance that is affected by an enzyme c) forms the dentine of teeth e) is as easily affected by temperature as an enzyme is In enzyme action a) an enzyme precursor forms a complex (combination) with the enzyme b) large molecules are always reduced to smaller ones c) a given enzyme may react chemically with a large numbers of molecules d) the substrate is the substance acted on e) a high concentration of enzyme molecules is necessary for prOper catalytic action The role of vitamins in metabolism is that they combine with other substances to form larger molecules called a) coenzymes b) hormones c) substrates d) pangenes e) antienzymes Enzymes a) are highly resistant to the action of strong acids b) can easily be made in a laboratory c) are not affected by temperature changes d) are unchanged by the reactions they bring about e) are inorganic compounds Which of the following is the most complex compound? a) protein b) amino acid c) nitrate d) inorganic nitrite e) ammonia A catalyst is a) a substance which affects the rate of a chemical reaction b) a powerful oxidizing agent c) a substance that does not take place in any part of a chemical reaction d) a strong electrolyte e) the negative pole of an elctrolytic cell Which of the following is NOT a compound? a) water b) sugar c) hydrogen d) salt e) carbonate The atom can be seen by means of a) an electron microscope b) a compound microscope c) a geiger counter d) no instrument now available d) a spectroscope The most abundant compound in protoplasm is a) protein b) carbohydrates c) fat d) sugar e) water 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 84 The elements always contained in proteins are a) carbon, hydrogen and oxygen b) carbon. hydrogen, sulfur and. phosphorous c) carbon, hydrogen, oxygen and nitrogen d) hydrogen and oxygen e) calcium, sulfur, potassium and iron Simple. sugars, double sugars, starches and cellulose belong to a group of organic compounds known as a) fats b) proteins c) carbohydrates d) enzymes e) amino acids The substance which in the body acts as a solvent for mineral salts and many organic compounds, that favors the movement of materials, and that changes temperature slowly is a) protein b) water c) fat d) carbohydrate e) enzyme An enzyme is a) an organic catalyst b) an organic digestive Juice c) an organic hormone d) an acid 8) a complex inorganic protein The number of different COMPOUNDS now known to exist is a) greater than b) less than c) the same as the number of ELEMENTS known to exist Which class of foods yields the greatest number of calories per unit? a) proteins b) fats c) vitamins d) carbohydrates e) mineral salts Any substance which tends to minimize the fluctuations in the hydrogen ion concentration within the cell is called a(n) a) acid b) salt c) buffer d) catalyst e) amino acid the units of structure of proteins are a) glycerine b) amino acids c) monosaccharides d) fatty acids The units of structure of fats are la) glycerol and fatty acids b) amino acids c) monosaccharides d) fatty acids e) none of the above Simple substances which can be neither decomposed nor transferred into one or another by ordinary means is a) an element b) a heterogeneous mixture d) a homogeneous mixture e) a compound e) none of these 85 31. Which one of the following terms includes the other four? a) molecule b) atom :3) element d) compound e) matter 32. When a fat is synthesized. a) fatty acids combine together b) simple sugars combine together c) fatty acids combine with glycerol d) glycerol combines ‘with a simple sugar e) amino acids combine to form large molecules 33. If distilled water were tested with a pH meter, its pH should be a) 2 b) 7 c) 13 d) 4 e) 8 SHORT’ ANSWER: answer the following questions completely. You do not need to use complete sentences. Be sure diagrams are well labeled. 34. List three properties of water that make it important to the body 35. Make a diagram to show the arrangement of protons, neutrons and electrons in a carbon atom. 36. What kind of bond (ionic or covalent) would an atom be likely to form if it had one or two outer electrons? 37. Use chemical symbols to write the formula for carbon dioxide. 38. Write an equation (it does not have to be balanced) to show that water and carbon dioxide combine to form carbonic acid H2C03. 39. What is the pH scale used to express? 40. Define the term: chemical formula. 41 Define acid and give an example of one. 86 PHYSIOLOGY POST-TEST FOR CHEMISTRY Fall 1988 Name Date Hour Read all of the following questions carefully and answer them according to the instructions provided. MULTIPLE CHOICE: Select the lettered choice that best answers each question. 1. Chemically, the protoplasm of cells consists of a) mostly rare elements b) hundreds of different elements c) elements, each of which usually retains its own elemental characteristics d) mostly common elements e) mostly elements with high atomic masses The four most common elements in the human body are a) carbon, hydrogen, oxygen and chlorine b) carbon, oxygen, nitrogen, and chlorine c) carbon, hydrogen, nitrogen and calcium d) carbon, hydrogen, oxygen and iron e) carbon, oxygen, hydrogen and nitrogen Which of the following statements regarding pH is true? a) a dilute solution of almost any acid will have a pH of somewhere above 7 b) the pH scale is used to indicate the acidity of solutions, but not the alkalinity c) a solution of pH 4 is twice as acidic as one with pH 2 d) a solution with ph 8 is more acid (less alkaline) than one with pH 9 e) none of the above is true A molecule of carbohydrate contains the chemical elements a) nitrogen, carbon and hydrogen b) calcium, carbon and chlorine c) carbon , hydrogen and oxygen d) carbon, oxygen and phosphorus e) carbon, oxygen and nitrogen 10. 11. 87 C631206 a) is an example of a structural formula b) represents a hexose c) is a form of glycerol d) is a product of the digestion of proteins e) is formed by the digestion of fatty acids A molecule of fatty acid a) has the same structural formula as a monosaccharide b) has the same empirical formula as a monosaccharide c) is either saturated or unsaturated d) has an equal number of carbon and oxygen atoms e) contains nitrogen Amino acids a) are a true acid b) are present in carbohydrates c) are present in cellulose d) contain nitrogen e) are also called fatty acids Each unit compromising the DNA macromolecule is made of a) a nitrogenous base b) a five carbon sugar c) a phosphate d) all of the above e) a nitrogenous base and a phosphate. Genetic information for cell use is replicated from deoxyribonucleic acid into another type of nucleic acid a) called amino acid b) found only in the nuclei of cells c) having a more complex molecular structure that DNA d) after DNA has passed from the nucleus to the cytoplasm e) known as ribonucleic acid (RNA) The expenditure and transformation of energy which is the basis for all life processes a) is called anabolism b) is also the basis for organic evolution c) depends upon plant and animal hormones d) is controlled by chemicals called enzymes e) may be related mathematically using the Hardy-Weinberg law The main function of an enzyme is to speed up or slow down a specific chemical reaction. This statement ‘is most closely related to which of these life characteristics? a) irritability b) metabolism c) reproduction <1) adaptability e) growth 12. 13. 14. 15. 16. 17. 18. 19. 88 In enzyme action a) an enzyme precursor forms a complex (combination) with the enzyme b) large molecules are always reduced to smaller ones c) a given enzyme may react chemically with a large numbers of molecules d) the substrate is the substance acted on e) a high concentration of enzyme molecules is necessary for proper catalytic action The role of vitamins in metabolism is that they combine with other substances to form larger molecules called a) coenzymes b) hormones c) substrates d) pangenes e) antienzymes When enzymes act a) the energy for their actions is derived from the enzymes themselves b) the resulting products are called substrates c) an intermediate enzyme-substrate complex is probably formed d) the enzymes are destroyed during the enzyme action, so much be constantly produced e) their reactions are not affected by the pH or concentration of the substances acted on. Enzymes a) are highly resistant to the action of strong acids b) can easily be made in a laboratory c) are not affected by temperature changes d) are unchanged by the reactions they bring about e) are inorganic compounds Subdivision of large, complex molecules into their smaller, simpler components is accomplished by chemical reaction known as a) condensation b) hydrolysis c) plasmolysis d) synthesis e) agglutination Which of the following is NOT a compound? a) water b) sugar c) hydrogen d) salt e) carbonate The atom can be seen by means of a) an electron microscope b) a compound microscope c) a geiger counter d) no instrument now available d) a spectroscope Which of the following groups of elements make up almost 99% of the protoplasm of organism? a) hydrogen and oxygen b) carbon, hydrogen, oxygen and nitrogen c) carbon, hydrogen and oxygen d) carbon, hydrogen, oxygen, sodium and phosphorous 20. 21. 22. 23. 24. 25. 26. 27. 89 The most abundant compound in protoplasm is a) protein b) carbohydrates c) fat id) sugar e) water Simple sugars, double sugars, starches and cellulose belong to a group of organic compounds known as a) fats b) proteins c) carbohydrates d) enzymes e) amino acids The substance which in the body acts as a solvent for mineral salts and many organic compounds, that favors the movement of materials, and that changes temperature slowly is a) protein b) water c) fat d) carbohydrate e) enzyme Which of the following statements best characterizes fats? a) they are synthesized from amino acids b) they contain hydrogen and oxygen in the same proportions as these elements occur in water c) They are made up of more complex molecules than are proteins d) they serve primarily as a protoplasm-building material e) they have less oxygen in proportion to hydrogen than do carbohydrates An enzyme is a) an organic catalyst b) an organic digestive Juice c) an organic hormone d) an acid e) a complex inorganic protein The number of different COMPOUNDS now known to exist is a) greater than b) less than c) the same as the number of ELEMENTS known to exist Which class of foods yields the greatest number of calories per unit? a) proteins b) fats c) vitamins d) carbohydrates e) mineral salts Carbohydrates, fats and proteins always contain at least a) carbon, hydrogen and oxygen b) carbon and hydrogen but not necessarily oxygen c) carbon and oxygen but not necessarily hydrogen d) oxygen and hydrogen but not necessarily carbon e) nitrogen 28. 29. 30. 31. 32. 90 Which of the following statements best describes an organic substance? a) it is a material which is less combustible than an inorganic substance b) it is a material capable of being produced by a living organism only c) it is a long chain carbon compound that can be easily synthesized in either the body of a living organism or in the laboratory d) it is a compound which always contains nitrogen, sulfer and phosphorous e) it is the bridge between living and non-living matter Any substance which tends to minimize the fluctuations in the hydrogen ion concentration within the cell is called a(n) a) acid b) salt c) buffer d) catalyst e) amino acid the units of structure of proteins are a) glycerine b) amino acids c) monosaccharides d) fatty acids Simple substances which can be neither decomposed nor transferred into one or another by ordinary means is a) an element b) a heterogeneous mixture d) a homogeneous mixture e) a compound e) none of these Which one of the following terms includes the other four? a) molecule b) atom c) element d) compound e) matter SHORT ANSWER: answer the following questions 33. 34. 35. 36. completely. You do not need to use complete sentences. Be sure diagrams are well labeled. List three properties of water that make it important to the body Make a diagram to show the arrangement of protons, neutrons and electrons in a carbon atom. What kind of bond (ionic or covalent) would an atom be likely to form if it had one or two outer electrons? Use chemical symbols to write the formula for carbon dioxide. 37. 38. 39. 40. 91 Write an equation (it does not have to be balanced) to show that water and carbon dioxide combine to form carbonic acid H2c03 What ion causes a solution to be an acid? Define the term: chemical formula. Define acid and give an example of one. APPENDIX E STUDENT INTERVIEWS 92 INSTRUMENT FOR INTERVIEWING STUDENTS ABOUT CHEMISTRY UNIT What do you remember most about the unit on chemistry? Why? What part of the unit has been most helpful with the other topics you’ve studied? Why? What do you think was easiest to learn? Why? What was the most difficult to learn? Why? Do you think the time spent on the unit was appropriate, too long, or too short? Why? Would you rather see more (or fewer) labs? Why? Do you find it easier to learn from the labs or text? Why? 93 STUDENT INTERVIEWS CONCERNING CHEMISTRY UNIT The Physiology class this year is made up of a mix of tenth, eleventh and twelve grade students. They all expect to attend college. ‘The chemistry unit was taught from September 12 to October 14, 1988. Interviews were conducted April 5 and 6, 1989. The students took a retest of the material on April 3, 1989 to compute retention and remind them of the unit. The criteria for selection of students for interviews was based on a set of random numbers generated by the computer and modified by absences and volunteers. One of the two students with low grades refused to be interviewed, and the second was absent both days. The following questions were put to the students. Answers are written in order given. 1. What do you remember most about the unit on chemistry? Why? What part of the unit has been most helpful with the other topics you’ve studied? Why? What do you think was easiest to learn? . What was most difficult for you? Why? Do you think the time spent on the unit (6 weeks) was appropriate? Why or why not? Would you rather see more or fewer labs? Why? Do you find it easier to learn from the book or the labs? \lOl 0148(4) N Student #14 is an A/B student. He must study to do well on the tests and does daily work consistently. When asked what he remembered most on the chemistry unit, he could not remember anything. He was the first person to be interviewed. Student #10 is an A/B student. He is conscientious about tests and daily work, but good grades do not come easy for him. 1. The, ah, symbols for the elements. [no answer on why] probably the unit on chemistry the atoms [no answer to why] the bonding, they’re hard to separate Just right because it wasn’t too long to make you bored and it ‘wasn’t too short so you didn’t get enough fewer, too tedious reading text [no answer to why] 01wa \101 94 Student #8 is a high achiever. He consistently sets the curves on tests and quizzes. He takes his book home almost every night and actually does the assigned reading. 1. covalent bonding ’cause I had a little bit of it in ninth grade 2. probably when we learned all the names of the elements and symbols and everything so because there’s a lot of that in like the nervous system and the intestinal system 3. um, hum let’s see 4. can’t really remember anything that was easy or difficult 5. it was fine the way it was, if you make it any longer you sort of get out of the class because its physiology. not chemistry so 6. probably Just around where it was 7. I’d say the textbook, but then you can see it work in the labs, but I learn more from the text. Student #4 is a B student. I think she is working a little over capacity because she is competing with her younger brother who is also in the class. the element chart because we used it a lot the element chart and when we did the pH and stuff like that the pH because it Just was the element chart because there was so many to learn . it was a little long fewer cause I don’t like labs . textbook! \lOlUi .50) NH Student #9 is a C student and has to work very hard to keep her grade at that level. She focuses on facts rather than concepts. . the elements the pH scale, because I like [unintelligible for rest of answer] 'learning to work with the pH scale the elements and compounds cause it was difficult for me . [no answer] more, I like labs the labs 41mm Ah) NH 95 Student # 19 is a C/B student. He could do better but tends to be a little lax on the daily work. 1. ah, pH [long pause, no answer to why] 2. [no answer] 3. um, ah, the section on bones and muscles [interviewer "that wasn’t in the chemistry unit."] Oh, ah, I, I... 4. the... um... the formulas 5. no, it was about....right, because it was a... um... a complex subJect 6. fewer,[no answer to why] 7. the lab because you experience it instead of reading it. Student #11 says she does not understand anything that is going on in the class and at one time had contemplated dropping the course, but she consistently maintains a B average. 1. um. I remember the stuff about enzymes and about different substances that, you know,[rest of answer unintelligible]. We worked on that a lot and did stuff about it and then we.... 2. well, like the stuff we learned about enzymes that you use with other stuff about your body 3. well, like when we did all those labs about the enzymes it makes it easy to remember and everything 4. well, I can’t remember like all the different names and different functions and that. I know ’em but I don’t know all the names and stuff 5. well, I think that was about the right amount of time, not too long or too short 6. um, I’d say more because labs are pretty easy. You don’t have much homework or anything, you’re Just working 7. from a lab because you can see it and touch it. If you read you can’t really visualize what’s happening but a lab it’s there and it shows you. Student 96 #2 is a C/D student. She is active in extracurricular functions and often neglects her daily work as a result. She does poorly on most tests. 7. the symbols. There was Just a lot of them to get mixed up Just knowing what the things were and it wasn’t as much trouble and the units were mentioned and we knew what they were the structural formulas were easy to remember Just remembering them more would be better, but it wouldn’t be the class, you need to spend an equal amount on everything. well. we did a lot at once and then we didn’t and then we did a lot again, it would be better spread out and then more wouldn’t matter The labs, its hand’s on Student #17 probably is able to understand concepts covered in labs easier than most of the students in the class. He has improved much since the start of the year and now carries an A average. He scores high on the tests and does most of his daily work. 1. the pH scale and buffers ’cause of all the color ' 2. um, the part with the pH scale cause we did a lot of that when we went to the food stuff, it had all the ph scale 3. the pH scale 4. um, can’t remember.... the buffer system because you had to remember all the different stuff 5. I think that it was pretty good 6. We did a lot of labs 7. From the labs APPENDIX F STUDENT SURVEY ON CHEMISTRY IMPORTANCE 97 SURVEY FORM FOR CHEMISTRY UNIT Please answer the following questions by circling the appropriate response. Five indicates a strong positive res onse such as very much or quite often. One ind cates a strong negative response such as not at all or never. Each topic will have three areas to give your opinion on: . A. How often do you run across this concept in your dallg life? this? B. ow often do you apply what you learned about °C. How important do you think it is in your life? Acid/Ease balance B C Atomig bonding B C Atomig structure B C Buffers A B C Carbogydrates 2 Catalxst/enzymes 8 Chemigal reactions B C Compognds 8 Elemegt or molecular symbols B C Elements A B C Indicators B Li idc p s A C Metabglism B c _ HHH D-b - o—n—u—n HMO-5 HHH HHD—O Hp... HMO-e HHH HHH Hear-a HMO-b HHH NNN N N NNN NNN NNN NNN NNN NNN NNN NNN NNN NNN NNN (1)0)0) 0) 0) 0)0)0) 0)0)0) 0)0)0) (1)0)0) (1)0)0) (1)0)0) (1)0)0) 0)0)0) (1)0)0) (1)0)0) 0)0)0) AAA A A AAA AAA AAA AAA AAA AAA AAA AAA AAA AAA AAA 010101 01 01 010101 010101 010101 010101 010101 010101 010101 01010) 010101 010101 010101 98 555 4.4.4. 333 222 111 555 4.4.4. 333 222 555 4.4.4. 333 222 111 n ABCIABC ABC H D. Prote Salts 99 Survey for Chemistry unit A. How often do you run across this concept in your daily life? B. How often do you apply what you learned about this? C. How important do you thik it is in your life? Acid/base balance b 111111111222233333 1.78 c 111111222222233344 2.06 a 111122222222333444 2.28 Atomic Bonding a 111111111122233344 1.83 b 111111111222233344 1.89 c 112222222233333355 2.56 Atomic Structure a 111111111122223344 1.78 b 111111111222223344 1.83 c 111122222222333334 2.17 Buffers a 111111111222223444 1.89 b 111111122222222344 1.89 c 111111222222233344 2.06 Carbohydrates a 111111334444445555 3.11 b 111223334444444455 3.22 c 112233333444444555 3.33 Catalyst/enzymes a 111111112222333444 2.06 b 111111122222223334 1.89 c 111122222222333345 2.28 Chemical reations a 111111122223334455 2.33 b 111112222233333444 2.33 c 111112222333344455 2.61 Compounds a 111111222222333445 2.22 b 111122222233333345 2.39 c 111122222223334444 2.39 Element or molecular symbols a 111111111123333445 2.06 b 111111222222233444 2.11 c 112222223333344444 2.72 Elements a 111111112222333345 2.06 b 111111222222233444 2.11 c 112222223333344444 2.72 Indicators a b c Lipids a b c Metabolism CB roteins alts OUDIUJOU'W'OOO'OI'OOUD 100 111111111222222434 111111111222222333 111111222222223334 111122223333344555 111222233333344445 122222223333334555 111111233334444455 111222233333444444 112222233334444445 111111122223333445 111112222222233333 111112222223333344 111112222223344555 112223333344444445 122333333334455555 111111223333444555 111222223334444555 122222233333444455 I-ho—bO-b (DNN 0)0)N NNN NNN NNN .78 .67 .94 .78 .78 .89 .78 .78 .94 .22 .22 .56 .44 .72 .94 .00 APPENDIX G TEST SCORE DATA 101 mamvm.mmmxmm.vm__ mwm «vm.~am amm.w_m~ mvw «av.mam cam mesa ca.~m amo.mm mm.- »m~._m www.mo m~.Nm »w_.om m.m~ noaueo>a vv amm.oa am gamma www.ma av wv woman macaw oz o“ a as am «mm.am a_ xam.o~ «am.aw av vm xmc.av av an o_ z w: "v xom.vo hm »_v.o~ aco.ac av vv xam.am av vm o_ 2 >9 _v «om.vm am aam.m~ «a~.mm av «@ xaw.vm av a. o_ x on mv wom.ao mm xdm.om aco.am av vv no~.am av am a" 2 9: .v «om.vc an amm.wa «fiv.ma av wm ava.wv av mm c_ 2 av o uoo.o “Guam momma macaw oz «N_.o av m o“ m :2 av xm~.~m mm xav.v~ «nv.ma av wn xma.ov av v~ o_ m an an xm_.oa mm xmm.~m «am.a~ av am xva.mv av mm c— m ma o «99.: amo.ov xmm.aw av mm xmm.m~ av m_ o. m mm vm aco.om w" www.mm «mm.aa av on xoa.vv av mm "a 2 am a «oo.° - wwm.~v «am.aa av am ama.om av o. __ 2 mm mm www.mv m_ aav.v~ xmo.~m av mm www.mm av m. ~_ m a: ov xm~.«o mm amo.ov xmv.~a av mm »_w.om av m2 _~ m 3“ «N wma.mv v_ xv~.am www.mv av ~N umv.m~ av "u 2— m aw mm «oo.mv m_ xmv.- xoa.vv av «N umv.m~ av .u 2. m :4 mm www.mm 2N «oa.mv «mv.«a av mm xmv.- av a“ «g m a: on am~.mm @— amm.w~ xv~.am av mu »~m.om av m. __ m on a «oo.o . www.mu «mm.wm av mu aoa.o« av m N" x cm vm xma.mw mm xmv.- »o_.mm av 5N xmm.~m av m. N_ a mu ~_ woo.mm o «av.vm xoa.om av a" aaN.v_ av a - m =9 ovummoa cameo » ”Lasagna unease » ocean « a.a.mmoa Loom-umoaouaea » o_n_nmoa oeoomuoea uuaea xom Leousum L. ”Loom mmummoa <94: mmoom emma >msm~=m=o am\cma_ 102 1987/88 CHEMISTRY TEST SCORE DATA PHYSIOLOGY 1987 (one week on chemistry) Student sex grade post-score possible % grade GS M 12 28 42 66 67% EW F 11 33 42 78.57% TY F 11 35 42 83.33% JA F 10 23 42 54.76% GC F 10 37 42 88.10% KD F 10 21 42 50.00% EH F 10 31 42 73.81% JH F 10 33 42 78.57% LM F 10 29 42 69.05% SM F 10 28 42 66.67% KP F 10 16 42 38.10% JO F 10 29 42 69.05% DB M 10 21 42 50.00% SD M 10 27 42 64.29% JF M 10 32 42 76.19% RH M 10 24 42 57.14% PM M 10 28 42 66.67% BR M 10 18 42 42 86% LK F 12 33 42 78 57% JP M 11 26 42 61 90% RS M 11 21 42 50 00% TC F 10 23 42 54 76% AK F 10 30 42 71 43% KK F 10 30 42 71 43% SL F 10 25 42 59 52% SA M 10 38 42 90 48% GB M 10 32 42 76 19% DH M 10 33 42 78 57% MH M 10 20 42 47 62% HM M 10 20 42 47 62% BS M 10 22 42 52 38% Averages 28.12 66. 103 1986/87 CHEMISTRY TEST SCORE DATA PHYSIOLOGY 1986 (two weeks on chemistry) Student sex grade post-score possible % grade MD M 12 16 22 72.73% PH M 12 20 22 90.91% SB F 10 21 22 95.45% DC F 10 9 22 40.91% SC F 10 21 22 95.45% AC F 10 14 22 63.64% JC F 10 20 22 90.91% CC F 10 12 22 54.55% HF F 10 15 22 68.18% 88 F 10 22 22 100.00% DG F 10 17 22 77.27% KG F 10 18 22 81.82% JH F 10 22 22 100.00% PH F 10 2 22 9.09% MH F 10 20 22 90.91% JA M 10 16 22 72.73% CA M 10 13 22 59.09% PB M 10 16 22 72.73% BD M 10 18 22 81.82% JL M 12 15 22 68.18% KM F 10 15 22 68.18% TO F 10 12 22 54.55% RS F 10 18 22 81.82% RS F 10 22 22 100.00% BM M 10 15 22 68.18% JM M 10 20 22 90.91% MS M 10 20 22 90.91% CS M 10 14 22 63.64% NS M 10 21 22 95.45% BS M 10 21 22 95.45% AW F 12 14 22 63.64% RH F 10 19 22 86.36% DH F 10 13 22 59.09% JK F 10 7 22 31.82% TL F 10 12 22 54.55% HM F 10 21 22 95.45% NM F 10 14 22 63.64% T0 F 10 17 22 77.27% CP F 10 4 22 18.18% LP F 10 18 22 81.82% AR F 10 13 22 59.09% TT F 10 17 22 77.27% RT F 10 12 22 54 55% SD M 10 14 22 63 64% SM M 10 9 22 40 91% AVERAGES 15 55 70 69% APPENDIX H COMPUTERIZED ANALYSIS OF MULTIPLE CHOICE PORTION OF TESTS 10¢i NmaV.N hzw2w¢3mh~4~m<~4m¢ zomo¢psaoeeeso amen zhssu~em~o am»_ no zoehsmeapmHQ ¢<233m mmZOammz Swhm oo—Iunlwmmaou ommmiwanm mun mmo<¢u n44 CNFDQSOU 3m! 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XX XX XXXXXXXXX 20) XX XX XX XXX X 5N XXXXXXXXXXXXXXXXXX :v-O XX XXX XXX XXXX 22 £1222 4.: 0032000 I: ZMIIJM rue-cram o It) 26* H>BE~MWZBE '0 means: MEI-J EQmMEE-‘tflz: 3 00048>><>Ozz kit-4:) X>OZ 4.: 23:2 HHNHHMQEZOHHwHt—a 0') 0 r-arucummmzt—m t—ccnrummmz APPENDIX J DETAILED LABORATORY EXERCISES 111 “ATOM“ LAB Purpose: To determine the location and composition of the "nucleus“ of the "atom" Test: You will be given a clay ball containing a small common household or classroom item. You will also get a dissecting probe. Make five probes into the ball, writing down what you found after each one. You must make each probe in a different location. You will probably want to make a record of where you make the probes. After five pokes, draw the location and shape of the nucleus of your atom. Now, you may make 5 more pokes. Again, write down what you find with each one, and at the end, draw the location and shape of the nucleus. You may make five more probes. (The limit is 15! I will count.) Draw the location and shape of the nucleus. Using your written observations, tell what you think is in the clay ball, and why you think it is what you think it is. After I have read your conclusion, you may “split“ your atom. 112 BLACK BOX LAB I Purpose: To determine the shape of the maze inside the box using all your senses but sight. Test: Carefully roll, twist, shake, or otherwise manipulate the black plastic box that contains a ball bearing and a maze. From the feel and sound of the ball moving inside the box, determine the shape of the maze. Write down all your observations and write your conclusions using the observations you took. You will need to have a drawing of the maze before you can see what your maze is. Then, compare what you thought you had with what you did have. How can you account for the differences? BLACK BOX LAB II Purpose: To determine the contents of a small cardboard box containing small household items without using sight. Test: Use all your senses, except sight to try and determine what is in the box. You may shake, slide, roll or drop the box. Be sure to write down each manipulation. This will be the procedure part of your lab write up. Write down what happened during each manipulation. This are the observations. If you wish you may use some other items to help you test. You may wish to use a magnet, or balance, or you may wish to put the obJects you suspect you may have into another box to see if they sound the same. Just make sure everything you do gets written down as a procedure. You may not open or poke into the box. When you are fairly sure what is in the box, write your conclusions telling me why you think that, using observations to support your guesses. A box will be opened tomorrow so you can check your guesses. 113 ACID AND BASE LAB (adapted from a Chemtech kit) Introduction: Acids and bases have long been known to chemists. Bases cause foods to have a smooth "soapy" feel when rubbed between tow fingers. They have a bitter taste and turn litmus paper blue. Acids make foods taste sour and turn litmus paper pink. Indicator dyes, in addition to litmus, turn various colors according to the strength of acid or base solution that is mixed with the indicator. An acid in water contains more hydrogen ions than hydroxide ions. A base produces an excess of hydroxide ions. Pure water, which is "neutral", exists mostly as water molecules, but to a very slight degree, it does break up into an equal number of hydrogen and hydroxyl Ions. HOH <--> 3*(aq) + 0H'oo 158 SV.’IQ I C33; I :3: . - SV-I.Iop (‘13 [2... $653.. p boat’sAU I, so...‘ - l\.\.U (‘13. 2’ s2. 5 oz 2... .5. mm .o .E :5 :2 :a a2 a ma 5 .5 I3“ 8.6.x as. 3.. 57...”... c... It...” a... in a: a... 2. 2... 9. a... $.53... :. 2.... Reese... me :K 3 can... 8 .3 as 2...... 2:53.... I $.63. - (1...... I .612. .35.. I 53.1! IS8§5I (5.: I548}; I 3;... I 5.2.2.. 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