AP Biology Review Chapters 6-8 Review Questions Chapter 6: Metabolism: Energy and Enzymes Chapter 7: Photosynthesis Chapter 8: Cellular Respiration

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1 AP Biology Review Chapters 6-8 Review Questions Chapter 6: Metabolism: Energy and Enzymes 1. Understand and know the first and second laws of thermodynamics. What is entropy? What happens when entropy increases? 2. What are the biochemical reactions in organisms collectively known as? 3. Know endergonic and exergonic reactions in terms of ΔG and energy of products and reactants. Which type of reaction is spontaneous? 4. Why are some reactions coupled? 5. What is the chemical structure of ATP? 6. Where is the energy stored in ATP and how is it released? 7. Know enzymes. Are enzymes used up in a reaction? How do enzymes work? How are enzymes affected by temperature, ph, alcohol and distilled water? 8. What is the energy of activation? How do enzymes affect the energy of activation? 9. What is the currently accepted model of enzymes and substrates? 10. What is lactose intolerance? How can a person with lactose intolerance avoid the side effects of it? Chapter 7: Photosynthesis a) Know the structure and function of the organelles involved in photosynthesis. Understand the Z- scheme and Calvin cycle diagrams to be able to explain the process of photosynthesis in detail. b) In what organelles are ATP synthase complexes found? What is the purpose of ATP synthase complexes? c) How do some poisons function? d) Know the chemiosmotic theory. How is an H + gradient established across the membrane? e) What happens to a molecule when it has been oxidized? Reduced? (LEO GER, OIL RIG) f) What organisms are capable of photosynthesis? (Think of ALL of them) g) Where does the electron transport chain occur in prokaryotic vs. eukaryotic organisms? h) What are units of energy of light called? Be familiar with absorption and action spectra. Understand what color light is reflected and absorbed by photosynthetic organisms. i) What is negative feedback? Be able to recognize or give an example of negative feedback. j) What happens when the stomata of a leaf closes? What is a possible negative side effect of stomata being closed? Know the differences and similarities in C 3, C 4, and CAM plants Chapter 8: Cellular Respiration 1. Know the three/four reactions (location and steps) of cellular respiration. 2. Know how many ATPs, NADHs, and FADHs are used or produced in each step of cellular respiration (both aerobic and anaerobic). Make a chart if it will help you organize the information. 3. When and how many CO 2 are produced? (HINT: it occurs in two of the four parts of cellular respiration) 4. What molecule is the primary energy carrier between the Krebs cycle and the ETC? 5. What molecule is the final electron acceptor in the ETC? What is made when it accepts electrons? 6. What does the flow of electrons in the ETC directly and indirectly accomplish? 7. Understand the differences between chemiosmosis, ETC, ATP synthase complex, oxidative phosphorylation and substrate-level phosphroylation. 8. Know and understand the process of anaerobic respiration and why it occurs. What two types of fermentation can occur? In which organisms do these processes take place? 9. What percentage of energy in glucose is captured as ATP during aerobic respiration? Fermentation? 10. What must happen to fats or proteins before they can enter cellular respiration pathways? How many of the 20 amino acids can humans NOT produce? What are they called and why?

2 Chapters Question 2 ATP and GTP are primary sources of energy for biochemical reactions. a) Describe the structure of the ATP or GTP molecule. b) Explain how chemiosmosis produces ATP. c) Describe two specific cell processes that require ATP and explain how ATP is used in each process. d) An energy pyramid for a marine ecosystem is shown below. Label each trophic level of the pyramid and provide an example of a marine organism found at each level of this pyramid. Explain why the energy available at the top layer of the pyramid is a small percentage of the energy present at the bottom of the pyramid Question 2 An experiment was conducted to measure the reaction rate of the human salivary enzyme -amylase. Ten ml of a concentrated starch solution and 1.0 ml of -amylase solution were placed in a test tube. The test tube was inverted several times to mix the solution and then incubated at 25 o C. The amount of product (maltose) present was measured every 10 minutes for an hour. The results are given in the table below. Time (minutes) Maltose Concentration ( M) a) Graph the data on the axes provided and calculate the rate of the reaction for the time period 0 to 30 minutes. b) Explain why a change in the reaction rate was observed after 30 minutes. c) Draw and label another line on the graph to predict the results if the concentration of -amylase was doubled. Explain your predicted results. d) Identify two environmental factors that can change the rate of an enzyme-mediated reaction. Discuss how each of those two factors would affect the reaction rate of an enzyme.

3 2010 Form B Question 1 Biological molecules can be separated by using chromatographic techniques. The diagram below shows the separation of several spinach leaf pigments by paper chromatography. Using the diagram below a) Explain how paper chromatography can be used to separate pigments based on their chemical and physical properties. b) Discuss the role of pigments both in capturing light energy and in converting it to the chemical energy of ATP and NADPH. c) Use the ruler shown above to determine the R f value of xanthophyll. Show your calculations Question 4 The element carbon is contained in all organic compounds. a) Discuss the role of photosynthesis and cellular respiration in carbon cycling in the biosphere. b) For THREE of the following, predict and explain the effect on the carbon cycle if: a. Decomposers were absent b. Deforestation occurred c. Volcanic dust accumulated in the atmosphere d. The average ocean temperature increased c) Explain how increased CO2 in the atmosphere results in greater acidification of oceans and describe the effect on marine organisms. Include in your discussion TWO examples of how human activity can increase atmospheric CO2.

4 2013 Question 2 Color Wavelength (nm) Violet Blue Cyan Green Yellow Orange Red An absorption spectrum indicates the relative amount of light absorbed across a range of wavelengths. The graphs above represent the absorption spectra of individual pigments isolated from two different organisms. One of the pigments is chlorophyll a, commonly found in green plants. The other pigment is bacteriorhodopsin, commonly found in purple photosynthetic bacteria. The table above shows the approximate ranges of wavelengths of different colors in the visible light spectrum. a) Identify the pigment (chlorophyll a or bacteriorhodopsin) used to generate the absorption spectrum in each of the graphs above. Explain and justify your answer. b) In an experiment, identical organisms containing the pigment from Graph II as the predominant lightcapturing pigment are separated into three groups. The organisms in each group are illuminated with light of a single wavelength (650 nm for the first group, 550 nm for the second group, and 430 nm for the third group). The three light sources are of equal intensity, and all organisms are illuminated for equal lengths of time. Predict the relative rate of photosynthesis in each of the three groups. Justify your predictions. c) Bacteriorhodopsin has been found in aquatic organisms whose ancestors existed before the ancestors of plants evolved in the same environment. Propose a possible evolutionary history of plants that could have resulted in a predominant photosynthetic system that uses only some of the colors of the visible light spectrum Question 5 Microsystis aeruginosis is a freshwater photosynthetic cyanobacterium. When temperatures increase and nutrients are readily available in its pond habitat, M. aeruginosis undergoes rapid cell division and forms an extremely large, visible mass of cells called an algal bloom. M. aeruginosis has a short life span and is decomposed by aerobic bacteria and fungi. Identify the metabolic pathway and the organism that is primarily responsible for the change in oxygen level in the pond between times I and II AND between times III and IV.

5 2017 Question 7 Many species of bacteria grow in the mouths of animals and can form biofilms on teeth (plaque). Within plaque, the outer layers contain high levels of oxygen and the layers closest to the tooth contain low levels of oxygen. The surface of the tooth is covered in a hard layer of enamel, which can be dissolved under acidic conditions. When the enamel breaks down, the bacteria in plaque can extract nutrients from the tooth and cause cavities. Certain types of bacteria (e.g., Streptococcus mutans) thrive in the innermost anaerobic layers of the plaque and are associated with cavities. Other types of bacteria (Streptococcus sanguinis) compete with S. mutans but are unable to thrive in acidic environments. a. Identify the biochemical pathway S. mutans uses for metabolizing sugar and describe how the pathway contributes to the low ph in the inner layers of plaque. b. Normal tooth brushing effectively removes much of the plaque from the flat surfaces of teeth but cannot reach the surfaces between teeth. Many commercial toothpastes contain alkaline components, which raise the ph of the mouth. Predict how the population sizes of S. mutans AND S. sanguinis in the bacterial community in the plaque between the teeth are likely to change when these toothpastes are used.