Cell Energetics Practice

Transcription

1 Cell Energetics Practice Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The ultimate source of energy for almost all living organisms is: a. heat. b. glucose. c. carbohydrates. d. lipids. e. the sun. 2. Which of the following statements is contrary to the first law of thermodynamics? a. When gasoline is burned, its energy is destroyed. b. Energy can be transferred from one form to another. c. Energy can be converted from one form to another. d. Matter can be converted into energy. e. The amount of energy in the universe is constant. 3. Only 20% to 30% of the energy stored in the chemical bonds of gasoline molecules is transformed into mechanical energy; the other 70% to 80% is dissipated as waste heat. Which statement explains this phenomenon? a. The first law of thermodynamics. b. The second law of thermodynamics. c. When energy is converted from one form to another, some of the energy is converted into heat. d. Both the first and second laws of thermodynamics. e. Both the second law of thermodynamics, as well as the observation that the conversion of energy involves some energy being converted to heat. Figure 7-1 Use the figure to answer the corresponding question(s). 4. Which of the following statements about Figure 7-1 is true? a. The reactants have more free energy than the products. b. The products have more free energy than the reactants. c. The figure represents a spontaneous reaction. d. The figure represents an endergonic reaction. e. The reaction is endergonic, and also the products have more free energy than the reactants. 5. Energy stored within the molecules of ATP is in the form of energy. a. kinetic

2 b. heat c. potential d. nuclear e. light 6. Which of the following statements concerning ATP is FALSE? a. It is a nucleotide. b. It is called the energy currency of the cell. c. It contains phosphate groups joined in a series. d. It stores energy for long periods. e. It contains phosphate groups joined by unstable bonds. 7. Select the compound that contains the most energy: a. AMP b. ADP c. ATP d. P e. Cannot determine using the information provided. 8. Select the phosphorylation reaction: a. glucose + fructose sucrose + H 2 O b. glucose + ATP glucose-p + ADP c. glucose-p + fructose sucrose + P i d. glucose + glucose maltose e. None of these are phosphorylation reactions. 9. Because enzymes affect the speed of chemical reactions without being consumed, they are referred to as: a. hydrogen acceptors. b. activation energy. c. catalysts. d. cytochromes. e. transformation proteins. 10. Which of the following is NOT a part of an ATP molecule? a. adenine b. ribose c. chlorophyll d. phosphate 11. Energy is released from ATP when a. a phosphate group is added. b. adenine bonds to ribose. c. ATP is exposed to sunlight. d. a phosphate group is removed.

3 Figure Look at Figure 8 1. All of the following are parts of an ADP molecule EXCEPT a. structure A. b. structure B. c. structure C. d. structure D. 13. Which structures shown in Figure 8 1 make up an ATP molecule? a. A and B b. A, B, and C c. A, B, C, and D d. C and D 14. In Figure 8 1, between which parts of the molecule must the bonds be broken to form an ADP molecule? a. A and B b. A and C c. B and C d. C and D 15. What happens during photosynthesis? a. Heterotrophs consume ATP. b. Heterotrophs produce ATP. c. Autotrophs consume carbohydrates. d. Autotrophs produce carbohydrates. 16. What happens when chlorophyll is struck by sunlight? a. The electrons in the chlorophyll molecule become energized. b. The chlorophyll molecule is broken into two parts. c. A chemical reaction turns chlorophyll into high energy carbohydrates. d. Energy from fat molecules is released.

4 Figure Which chemical shown in Figure 8 3 is an electron carrier molecule? a. H 2 O b. carbon dioxide c. NADP + d. oxygen 18. A student is collecting the gas given off from a plant in bright sunlight at a temperature of 27 C. The gas being collected is probably a. oxygen. b. carbon dioxide. c. ATP. d. glucose. 19. In the overall equation for photosynthesis, six molecules of carbon dioxide and six molecules of water result in a molecule of sugar and six molecules of a. glucose. b. water. c. oxygen. d. ATP. A. B.

5 Figure In Figure 8 4, why might the candle in jar A burn longer than the candle in jar B? a. Carbon dioxide produced by the plant allows the candle to burn longer. b. Chlorophyll produced by the plant allows the candle to burn longer. c. Glucose produced by the plant allows the candle to burn longer. d. Oxygen produced by the plant allows the candle to burn longer. 21. What are the products of the light-dependent reactions? a. oxygen gas and glucose b. ATP, NADPH, and oxygen gas c. ATP, carbon dioxide gas, and NADPH d. carbon dioxide gas, oxygen gas, and NADPH 22. The Calvin cycle is another name for the a. light-independent reactions. b. light-dependent reactions. c. photosynthesis reaction. d. electron transport chain. 23. What is a product of the Calvin cycle? a. oxygen gas b. ATP c. high-energy sugars d. carbon dioxide gas 24. If carbon dioxide is completely removed from a plant s environment, what would you expect to happen to the plant s production of high-energy sugars? a. More sugars will be produced. b. No sugars will be produced. c. The same number of sugars will be produced but without carbon dioxide. d. Fewer sugars will be produced at first, but then the plant will recover. 25. If you continue to increase the intensity of light that a plant receives, what happens? a. The rate of photosynthesis increases indefinitely with light intensity. b. The rate of photosynthesis decreases indefinitely with light intensity. c. The rate of photosynthesis increases and then levels off. d. The rate of photosynthesis does not change. Figure In which experimental setup shown above would you expect the Elodea plant inside the test tube to produce the LEAST amount of oxygen?

6 a. A b. B c. C d. D Figure Imagine that y-axis of each graph in Figure 8 6 describes the rate of photosynthesis. Which of the graphs represents the effect of temperature on the rate of photosynthesis? a. A b. B c. C d. D 28. Imagine that y-axis of each graph in Figure 8 6 describes the rate of photosynthesis. Which of the graphs represents the effect of light intensity on the rate of photosynthesis? a. A b. B c. C d. D 29. Which of the processes shown in Figure 8-2 do not use a cell s energy?

7 Figure 8-2 a. A c. C b. B d. D 30. During photosynthesis light energy is converted to the energy in chemical bonds. What also happens according to the predictions of the second law of thermodynamics? a. chemical energy is converted to light energy b. matter is lost in the process c. heat is released in the process d. the light and chemical energy are equal 31. The energy acquired in the light-dependent reactions is used in the light-independent reactions to build glucose molecules. How is this energy transferred from light-dependent to light-independent reactions? a. in the bonds of ATP and NADPH molecules b. in the bonds of 5-carbon ribulose molecules c. in the bonds of 3-carbon phosphoglycerate molecules d. in the bonds of carbon dioxide molecules 32. Infer why chloroplasts are found mostly in the leaves of plants. a. The large surface area of leaves allows for maximum light absorption. b. The waxy coating on the surface of leaves helps prevent evaporation. c. Chlorophyll interferes with the xylem and phloem in the stems and trunks of plants. d. The large surface area of leaves allows for contact with oxygen. 33. The reactions of the Calvin cycle are not directly dependent on light, but they usually do not occur at night. Which of the following statements explains why not? a. The Calvin cycle depends on products of light reactions. b. Carbon dioxide is not available at night. c. It is too cold at night for reactions to take place. d. Most plants do not make the 4-carbon compounds that would be needed for the Calvin cycle to occur at night. 34. Where does the oxygen used in cellular respiration end up? a. water c. NADH b. ATP d. glucose 35. The transfer of electrons from glucose to oxygen during aerobic respiration takes place in a stepwise fashion through a number of intermediates rather than by direct transfer. This is because: a. it is chemically impossible to transfer electrons directly from glucose to oxygen. b. the chemical intermediates donate some of their electrons in order to increase the electron pool. c. the energy of the electrons can be used to make ADP. d. the energy of the electrons can be used to make ATP. e. the energy of the protons can be used to make ATP. 36. How do organisms get the energy they need? a. by burning food molecules and releasing their energy as heat b. by breathing oxygen into the lungs and combining it with carbon dioxide c. by breaking down food molecules gradually and capturing their chemical energy d. by using the sun s energy to break down food molecules and form chemicals 37. Which of the following is NOT a stage of cellular respiration?

8 a. fermentation b. electron transport c. glycolysis d. Krebs cycle 38. What is the correct equation for cellular respiration? a. 6O 2 + C 6 H 12 O 6 6CO 2 + 6H 2 O + Energy b. 6O 2 + C 6 H 12 O 6 + Energy 6CO 2 + 6H 2 O c. 6CO 2 + 6H 2 O 6O 2 + C 6 H 12 O 6 + Energy d. 6CO 2 + 6H 2 O + Energy 6O 2 + C 6 H 12 O What are the reactants in the equation for cellular respiration? a. oxygen and lactic acid b. carbon dioxide and water c. glucose and oxygen d. water and glucose Figure Using Figure 9 1, which pairing matches the structures shown in the cell diagrams with the processes that take place within those structures? a. A: photosynthesis; B: cellular respiration b. C: photosynthesis; D: cellular respiration c. D: photosynthesis; E: cellular respiration d. E: photosynthesis; D: cellular respiration 41. Which process does NOT release energy from glucose? a. glycolysis b. photosynthesis c. fermentation d. cellular respiration 42. Photosynthesis is to chloroplasts as cellular respiration is to a. chloroplasts. b. cytoplasm. c. mitochondria. d. nuclei. 43. Glycolysis requires a. ATP. b. oxygen. c. sunlight. d. NADP +.

9 44. Which of the following is NOT a product of glycolysis? a. NADH b. pyruvic acid c. ATP d. glucose 45. The Krebs cycle does NOT occur if a. oxygen is present. b. oxygen is not present. c. glycolysis occurs. d. carbon dioxide is present. 46. The Krebs cycle produces a. oxygen. b. lactic acid. c. carbon dioxide. d. glucose. Figure What process do the arrows for oxygen going in and water coming out represent in the Figure 9 2 diagram of the mitochondria? a. electron transport b. fermentation c. glycolysis d. the Krebs cycle 48. Which of the following pass high-energy electrons to the electron transport chain? a. NADH and FADH 2 b. ATP and ADP c. citric acid d. acetyl CoA 49. Cellular respiration uses 1 molecule of glucose to produce approximately a. 2 ATP molecules. b. 4 ATP molecules. c. 32 ATP molecules. d. 36 ATP molecules.

10 50. Lactic acid fermentation occurs in a. bread dough. b. any environment containing oxygen. c. muscle cells. d. mitochondria. 51. The two main types of fermentation are called a. alcoholic and aerobic. b. aerobic and anaerobic. c. alcoholic and lactic acid. d. lactic acid and anaerobic.

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