Zelda L. Kravitz
Introduction
The information here enclosed is suggested as and introductory course in Freshman Science for those students who have been selected because of low mathematical ability to adapt to a laboratory oriented course serving as an introduction to Biology, Physics, and Chemistry, which will also serve as a basis for other science courses. The teacher has no choice in the selection of his or her students, or to pre-test in order to group them. Students who have taken Algebra in grade 8 (eight) are automatically steered to Biology as a freshman course with the idea that they only are college material and will take Physics or Chemistry which makes them eligible for college credits, to which Physical Science is not accorded the honor.
Since the skills of the students approaching this course are unknown; they arrive with their concept of a laboratory as “Is this where we have explosions?” “Aw, come on and do some experiments for us and blow up this place!”
Of course neither of these statements are followed through or planned for.
The purpose of this unit is to help the student to:
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1. Develop his skill in observing, obtaining, recording, analyzing problems dealing with matter.
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2. Handle equipment which either he has constructed or assembled.
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3. Learn scientific mathematical skills needed for an introduction to science.
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4. Understand his environment and his relation to it.
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5. Learn how chemicals, naturally found, and laboratory produced affect his behavior, and well-being.
Since the laboratory contains equipment graduated in the SI units (system international); and since the international metric system is a certainty for use eventually in the United States, we have to develop the concept of the Metric System and its basis of units of ten. To make the Metric System less difficult labs can be organized very quickly when the child is taught that meter designated by measures distance, liter symbolized by 1 measures volume, and mass is measured in grams symbolized by g.
To give the concept of units of ten (10) the abacus can be displayed showing each of the 10 balls comprising one line, and ten balls equal one line. thus each ball is 0.1 of a line. A simple way for a child to remember metric units is to show him that this unit is based on tens and moving the decimal point to the right or left increases or decreases by units of tens. Usually it is not necessary to go beyond the units of 0.001 or 1,000, so the student learns only three terms; meter, liter, and grams. Then the prefix with the decimal values which are the same are attached, and we are ready to move into an experiment, centi equaling 0.01, milli equaling 0.001 and kilo equaling 1,000. We can also introduce the thermometer at this point since the Celsius thermometer is based on units of one-hundred.
Before actually doing the measurements, laboratory equipment, baby bottles, soda bottles, small wrenches, advertisements of 98 mm watches can be shown, mobiles from cereal boxes, and labels can be constructed. It is also helpful to teach that the thickness of the fingernail is approximately one mm and the width of the little finger is one cm.
We have given the student the basic tools and now we proceed with our experiment. We have to set the form at first as a guideline, and as the year proceeds the student learns to set up his own problem. To suddenly thrust this onto him will frighten him.
Although we have the measuring tool, we also have at this time to develop the idea of what we are measuring. The general concept of matter that has mass.
We begin with the students body and handy materials: cigarettes, weighing of a hair, fingernail, paper clip, pencil, sheet of paper, etc. See Experiments I III.
If equipment is limited, the teacher can ditto a metric ruler for perhaps 20 cm, and the child can be given a copy to paste in his book. For the construction of a simple balance using a can cover, string, and a small piece of wood can be constructed. A paper clip (medium size) has been found to be an acceptable gram weight.
Knowing that matter occupies space and has mass, in the introductory experiments, we now need to learn something about the structure of this matter. However, to stimulate the child’s interest in matter’s structure, how matter acts and reacts, and why it does so, calls for a series of simple experiments first; and then we can develop the interest for and why things happen.
Purposely the three forms of matter have been omitted as a separate series, because more than anything else, liquid, solid, and gas are previously taught, and can be added incidentally. Plasma as a form of matter is not necessary in our discussion here, at this point.
Our world is made up of many things. Some are large like mountains, some are small like grains of sand on the beach, and others are like us. Our study of matter will help to explain how things are made up. The simplest kind of matter is the element and is made up of one substance, however, the elements are of two types. Some are natural and some are made artificially lasting fractions of seconds. Ninety-two are natural and 14 are manufactured or synthesized. This information is a long step from the days of Democritus in the fifth century who thought there were only four elementary substances: stone, air, fire and water. The smallest particle of the element is the atom, and everything in the world is made up of these atoms or combinations of atoms called compounds. Each element has been named and scientists have devised a shorthand method, acceptable throughout the world.
The atom has two main parts, the nucleus in the center and the electrons which circle in layers or tracks outside the nucleus. Inside the nucleus are two main substances called protons which have a positive electric charge; and neutrons which have no charge and are neutral. The proton is 2,000 times heavier than the mass of the electron. There are other particles in the atom. Atoms are very small. A quarter billion of them would measure only about 25.4 mm in length, however, most of the atom is empty space. Mesons are like a nuclear glue which holds protons and neutrons together. The mass of the meson is between that of the protons and electrons. There are two kinds of mesons called m, or pions. The lighter ones are called muons u and there are also neutral pions m’. Pions live 10-1
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seconds, mesons live 10-6 seconds. Bohr said the electrons travel in the orbits but when they jump from one orbit or path to another they give off radiant energy. Recently in 1974 when there was a high energy collision of matter, particles called leptons and hadrons were discovered. The hadrons are complex, and evidence seems to show they have not only an internal structure, but 100 kinds have been identified; and some of the hadron, that is the simpler part, is called a quark. There was another particle discovered called the lepton. There are four known leptons which include the electron and muons above mentioned and two kinds of neutrinos. The muon is about two-hundred times heavier than an electron. There is belief that quarks are so entangled inside the hadron that they can never be separated. Hadrons decay very rapidly and their lifetime is 10-2
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seconds; but they are a distinct type of matter.
An even newer particle called the Psi was discovered and led to the discoverers Samuel C. Ting and Burton Richter sharing the Nobel prize. The Psi particle has a lifetime of 10-20 seconds or 1,000 times that of the hadron even though it has the same mass. There is something yet undiscovered in the Psi which slows its decay. These recent discovered particles are the result of electrons and positrons being made to collide at high energy, and then the particles are sorted out from the remains of the collisions. The collisions take place in a piece of equipment called a Spear in which electrons and positrons circulate in opposite directions at nearly the speed of light while 10” electrons circle clockwise. Interestingly the electrons for this experiment are boiled off a hot filament as in a vacuum tube. Thus we see the scientists are constantly searching and finding new particles of matter.
All matter possesses chemical properties which determines how the matter acts. How matter combines with other matter will be our concern. As the electrons revolve in their orbits around the nucleus, the distance of the electrons from the nucleus and the number of electrons in the outer orbit will determine how the matter acts. The atom as the basic unit of matter can combine with another atom provided that the required number of electrons in each atom’s outer orbit doesn’t exceed the number of electrons based on the required amount.
Although the model of the atom has remained fairly stable over the years, a newer theory has shown that because of the high speed of the electrons an electron cloud is possible, similar to that of a whirling fan when you couldn’t see the separate blades, but only blurred ones.
When an atom gains one or more electrons or when it loses one or more electrons it becomes an ion and has an electrical charge. This gaining and losing of electrons results in the formation of compounds as a result of bonding together. The gaining and losing of the electrons does not destroy matter, but merely changes the appearance of the matter. The matter doesn’t go anywhere, it just shifts around. This is called the Law of Conservation of Matter. By following this law we can better understand what happens to substances when they combine whether by the use of heat, or chemical action, or even enzyme action within our bodies. Since everything is made of something, and since these somethings can combine or bond, this can also help to explain how matter is formed; and many combinations are possible. How electrons bond causes chemical reactions, and is changing the world.
When battery acid is dropped on clothing the remaining substance is black carbon. When sulfur fumes are released from car pollution they combine with oxygen in the air to form noxious fumes; and when these fumes combine with moisture in the air, buildings crumble slowly; statues lose some of their smooth surfaces. When proper food is taken into the body the chemicals in the mouth start the food on its trip through the body to become the necessary protein, by the action of chemicals.
By understanding the interaction of matter, we learn how nerve cells secreting hormones can influence the activity of brain cells for example. We learn how medications which are chemicals can influence thought and action; and how the lack of chemicals can cause alcoholism and mental breakdowns, or even blindness for example.
Since nerve cells communicate by releasing neurotransmitter chemicals at synaptic junctions, anything that interferes with binding of the neurotransmitter can disturb or change communication and disturb behavior. If a drug can be introduced that is the same as what is lacking, it can make it possible for the message to reach the cell, then the behavior can be normalized. For example, it was thought that Parkinson’s disease or shaking palsy was the result of degeneration of neurons near the center of the brain. It was found that the normal amount of dopamine needed was not naturally there, and the brain was depleted, so the tremor, rigidity, and movement delay resulted. With the addition of L.-DOPA given by mouth, the L.-DOPA stimulates the receptors in the brain and the patient is able to walk better. In certain mental illnesses such as Schizophrenia, there seems to be an excess of dopamine from the nerve endings causing an over activity in the person. Here a medication is given that blocks the excessive amount of dopamine, prevents over stimulation, and diminishes the symptoms of schizophrenia which is one of the most common mental illnesses; with such a scope of afflicted individuals, that the World Health Organization has launched an extensive research program to try to eradicate the illness due to the biochemical nature of the many dopamine receptors in the basal ganglia of the brain.
There also was a finding of an enzyme adenylate cyclase of the basal ganglia of the brain. With this finding there is a new method of screening of drugs as dopamine agonists (agents) against Parkinson’s disease or antagonists (agents against schizophrenia). With this information just about eight years old it is possible to evaluate illnesses by the presence of the dopamine and prescribe medication earlier.
Research has also shown that the role of the enzyme cyclase was not limited to the nervous system of vertebrates but also that the enzyme serotonin could affect insects and that drugs could affect neurotransmitter receptors. Insecticides such as Parathion and Malthion were developed.
Drugs affecting neurotransmitter receptors frequently produced changes that occurred in patients with neutral or neurological diseases. As a result miners who were exposed tomanganese poisoning when given antischizophrenic drugs show Parkinson symptoms. An interesting factor has been that L.S.D. can produce hallucinations similar to those of schizophrenics. These abnormal conditions may be genetic through mutation, or acquired through exposure to such toxins as manganese.
Many neurobiologists have shown that nerve cells respond to stimulation at the synopses, of one or more ions. This may change the ability of ions to flow across membranes, thereby changing the person’s voltage at that point. The neuron acts by absorbing the hundreds of chemical messages; and deciding when to react; research led to an understanding of such actions as to how glycogen (sugar) was broken down, protein metabolism, muscle contractions, pupilary dilation, intestinal peristalsis, and action of hormones and drugs that affect behavior. From this information, a better understanding of the brain, neurotransmitters, and the effect on genetic material that may in the end lead to changes of behavior, such as memory has been obtained.
Szent-Gyorgi has said, “If we want to find out something about the world around us we have to ask questions modestly, that is, do experiments.” With the above in mind, I have suggested the list of experiments to be done by students in order that they may understand the actions and reactions of matter so that they can better understand that which surrounds them; that what is taken into their body reacts and changes and that matter is not destroyed but merely changed around.
In the study of actions and reactions it is important for the student to realize that whatever is taken into the mouth may be affected by chemicals within his body, and for that reason a brief introduction to pharmacology is necessary as it has developed over the years; and is as old as man himself.
Early man looked for spirits to combat sickness. Alcohol was used to ease pain. Today we know it as an anesthetic. The bark of cinchona was the source of quinine to treat malaria. Curare was developed as a fatal poison. Thus, we had the beginning of pharmacology, drug actions and reactions, and chemical-biological reactions.
It is important to understand how chemical agents affect living processes, whether as the results of prescription or non-prescription drugs, living organisms, or plants, many of which are in the backyard or even the house. The most ancient records were found from 1600 B.C.E. in Egypt where 700 remedies were listed, and a person was able to choose which doctor he wanted. Babylonians lived in a world of demons, but doctors were separated from clergymen, and fees were set by law. In Greece and India the temple was the most common place of treatment, and in 500 B.C.E. a professor in India grafted skin from one person to another. In the sixth century B.C.E. smallpox vaccination was known, but did not reach Europe for 2,000 years. Hippocrates in 440 377 B.C.E. taught that disease came from natural causes, and that the body can recuperate with the help of fresh air, good food, purgatives, enemas, and blood letting. Galen originated such things as tincture of opium and vegetable drugs, and so influenced medicine for 1500 years. During the middle ages the Crusaders brought back medicinal information, and used their texts as late as the seventeenth century, for compiling hundreds of drugs. The Arab world developed accurate record keeping; Moslems established apothecary (drug) stores, and set state inspections, early consumer protection. After the thirteenth century pharmacies developed in Europe and the search for the “elixer of life” was developed. Florence, Italy issued the first book in the fifteenth century. Paracelsos believed the body was composed of chemicals in early sixteenth century; and he used tincture of opium, and mercury to treat syphilis. He said all drugs were poison, but the dosage changes it.
In 1628 Harvey gave drugs in the vein, and said they were better than by mouth. John Wepfer in the early seventeenth century performed experiments on animals. In 1776 a pharmacist’s apprentice stated a relationship between the amount of drug given and the biological response. In 1806 Frederick Serutrner isolated a pure vegetable drug and the synthetic manufacture of drugs began. Their reactions on the body was studied. Curare, which paralyzed the muscles, had to be studied to find what part of the body was affected by drugs. In the late nineteenth century the physiochemical reactions in cells with drugs, was studied. In 1841 James Blake stated that the chemical structure of drugs determines their effect on the body. In 1923 Ehrlich showed that drugs interact with biological material to produce certain effects. In 1842 it was found out that the effect of drugs can be changed or stopped by chemical conversion in one’s body. Pharmacology is now the study of reactions in a living organism by chemicals, except foods. About 1908 a Department of Pharmacology was expanded at the University of Michigan. In 1921 insulin led to the successful diabetes treatment. Chemistry supplies pure compounds,; physiology supplies experimental techniques all necessary for determining the biological effects of pure chemicals.
As we see, the development of pharmacology is one of using pure compounds. We can’t forget the danger in our home and outdoors, especially from plants. There are many poisonous plants, to eat and touch. Twelve thousand people have been poisoned in one year, especially children under five years of age, who pop anything into their mouths. People try to make “tea” out of weeds and unknown plants. Poison ivy as an irritant is the best known in this country. The toxin inside the leaf can cause a skin rash. Poison oak and sumac, the leaves and vines tomatoes and potatoes contain poisons called alkaloids. Cherry twigs contain cyanide. Seed kernels from peaches and apricots contain cyanide; “a cup of apple seeds may kill a person.” Green leaves of rhubarb contain oxalic acid poisonous, damaging human kidneys. Leaves of tomatoes, potato, and eggplant are so poisonous that handling may be fatal, causing rapid heartbeat and nervous system disorders. Jimpson weed grows in backyards; fox glove is a source of digitoxin affecting heart muscles; digitalis is made from fox glove and, as a medicine, makes heart muscles contract to pump more blood. Wisteria can poison children. Buttercup sap irritates the mouth. Lily of the Valley makes a poison like digitoxin and acts similarly. Even dandelion leaves can be poisonous, when eaten.
Matter is seen everywhere. Matter interacts for good or bad. Matter cannot be created or destroyed, but eating some matter may destroy you. Be Careful!
Many different experiments are included to aid the teacher in having enough of a variety to reach various ability students or to reinforce or review concepts already learned.
Many educators and philosophers worry about what children can’t do, we instead are concerned with all the things they can do; and reinforce those skills in which they are weak.
If at first children are afraid to work alone, groups of three or four can be started; and as confidence is gained and equipment becomes more available, individual experiments are most beneficial.
All children should write their own reports, and keep them, after correction, in a notebook. Experiments should be marked differently than regular work. For example, if anything is missing a “0” denotes this and the work is corrected and returned for recorrection.
