Biology 101 Lab Exam Ii Study Guide

LAB EXAM II STUDY GUIDE •

Lab Report #5—Mealworm Beetles

PART I

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Independent Variables: temperature of water

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Dependent Variables: metabolic rate (CO2 production)

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Standardized Variables: water volume, # or larvae, weight of larvae

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Most active= adults

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The metabolic rate continually increased the temperature.

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Independent Variables: life cycle stage

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Dependent Variables: metabolic rate

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The more activity, the higher the metabolic rate or CO2 level.

PART II

2nd most active= larvae

Least active= pupae

1. Aerobic respiration: the process of metabolism where sugars are broken down in the presence of oxygen; under aerobic conditions, respiration yields chemical energy, carbon dioxide, and water. C6H12O6 + 6O26CO2 + 6H2O + energy Glucose + oxygen carbon dioxide + water + energy

2. Metabolism: The chemical processes occurring within a living cell or organism that are necessary for the maintenance of life. In metabolism, some substances are broken down to yield energy for vital processes while other substances, necessary for life, are synthesized.

3. Metabolic rate: rate of metabolism; the amount of energy expended in a given period. 4. Poikilotherm: body temperature changes in with the environment; includes: invertebrates, fish, amphibians, and reptiles; (so-called “cold blooded” organisms whose heat source for body temperature regulation is external.) 5. Homeotherm: body temperature remains constant regardless of the environment; includes: birds, mammals; (so-called “warm blooded” animals whose heat source for body temperature is internal.) 6. Thermoneutral zone: when metabolic rate stays constant only over a relatively narrow range of air temperature; above this range, metabolism increases in a linear fashion with air temperature as animals try to keep their body temperature from rising (sweating/panting); below this range, metabolism increases in a linear fashion with decreasing air temperature as the animal “turns up the furnace” (increases metabolic heat production) to keep its body temperature from falling.

7. Life cycle: (of mealworm beetle)

8. CO2 Gas Sensor: used to measure concentrations of carbon dioxide. •

Lab Report #6—Photosynthesis

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Independent Variables: wavelength (red, blue, green)

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Dependent Variables: CO2

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The rate of photosynthesis in the dark is slower than the rate of photosynthesis in the light because the closer the light was to the plant, the greater light intensity it provided. This demonstrates that greater light intensity enabled more accelerated photosynthesis as more products were able to form faster.

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As light intensity increases, the rate of the light-dependent reaction, and therefore photosynthesis generally, increases proportionately. As light intensity is increased however, the rate of photosynthesis is eventually limited by some other factor. Chlorophyll a is used in both photosystems. The wavelength of light is also important. PSI absorbs energy most efficiently at 700 nm and PSII at 680 nm. Light with a high proportion of energy concentrated in these wavelengths will produce a high rate of photosynthesis.

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An increase in the carbon dioxide concentration increases the rate at which carbon is incorporated into carbohydrate in the light-independent reaction and so the rate of photosynthesis generally increases until limited by another factor. CO2 goes up in the light and down in the dark.

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Chlorophyll is the light absorbing pigment in plants…We see green when we look at a leaf because chlorophyll absorbs red and blue light while transmitting and reflecting green light. (Absorbs red, blue; reflects green)

 1. Photosynthesis: involves the use of light energy to convert carbon dioxide and water into sugar and oxygen. 6H2O + 6CO2 + light energy C6H12O6 + 6O2 2. Light-dependent stage: light is used to produce ATP and NADPH; requires chlorophyll to absorb light energy. 3. Light-dependent stage or Dark stage: uses ATP and NADPH from the light cycle to produce sugar (G3P). These reactions occur in a cycle called the Calvin Cycle. 4. ATP: a product of the light-dependent stage (adenosine triphosphate) 5. Wavelength: red, blue, and green filters.

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Lab Report #7—Enzymes 

Changes in pH can cause an enzyme to denature or change shape.

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Melanin is made by:

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Independent Variables: the amount of potato juice (catecholase)

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Dependent Variables: absorbency—Melanin

1. Enzyme: catalysts that speed up chemical reactions by lowering the amount of activation energy, which is required for the reaction to occur spontaneously. (require specific pH and temperature & ion/molecules to work) 2. Active site: region to which the substrate binds. 3. Substrates: (reactants) the molecules that you start with. 4. Reactants: see above ^^ 5. Products: results of a reaction; the molecules that you end up with. 6. Catechol: substrate 7. Catecholase: enzyme

Present in the cells of potatoes and fruits; cause potatoes/fruits to turn brown when injured; leads to the formation of benzoquinone.

8. Benzoquinone: form polymers called melanin, which darken as they get larger; THE DARKER THE SOLUTION, THE MORE LIGHT IS ABSORBED. 9. Calibrate: use blanks to calibrate (zero) the colorimeter. 10. Colorimeter: determines the concentration of products of the reactions between catechol and oxygen when the substrates are exposed to different concentrations of catecholase.

11. Denature: change shape

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Lab Report #8—DNA 

The smaller (lighter) fragments travel farther towards the bottom of the gel. The larger (heavy) fragments remain closer to the top.

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If there is a putative father involved who is not the biological father, there should be very little correlation of banding pattern between his DNA and the child’s.

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The child should have roughly ½ of its bands align with its mother, and the bands that do not come from its mother must come from its father. There should only be one father whose DNA matches these criteria.

1. DNA: Deoxyribonucleic acid 2. Restriction enzymes: cleave DNA at specific restriction sites. 3. Palidromes: DNA base pair sequences that are read the same leftright and v/versa (5’3’ end); the number differs among people

4. Agarose gel electrophoresis: a process used to separate DNA. 5. Anode: positive pole; the shorter the fragment, the more quickly it will move toward the positive pole 6. Cathode: negative pole; the longer the fragment, the more quickly it will move toward the negative pole.