Biol 101
Exam 3: Energy, Photosynthesis & Respiration
Fall 2006
Part I: Critical thinking questions
1. What does fermentation and alcohol production have to do with cell respiration?
2. What is the difference between aerobic and anaerobic respiration?
3. What are the stages of aerobic respiration?
4. If yeast cells are used to make a carbonated soft drink, would alcohol still be produced?
5. Why is oxygen important in cellular respiration…or… why do we breathe? In other words, what is the
molecular need for oxygen in cellular respiration?
6. Is energy created during cellular respiration?
7. ATP is produced during cellular respiration. However, it is also required. Explain.
8. What is the function of the 3 (or 4) stages of respiration?
9. How is ADP converted to ATP?
10. Explain chemiosmosis.
11. Explain substrate-level phosphorylation.
12. Why is acetyl Coenzyme A an important molecule in cellular respiration?
13. Oxidative phosphorylation involves redox reactions. Explain.
14. Why do we breathe? (The answer is not… “to live”… or…”because otherwise we would die”.)
15. Why do we respire?
16. What is the difference between respiration and breathing?
17. How do plants get ATP from glucose?
18. How do animals get ATP from glucose?
19. If glucose is burned (literally), the energy in it can be released as heat and light. W hat happens to the
energy in glucose when glucose is “burned” in aerobic cellular respiration?
20. What organelles can produce ATP? (Hint: Think about both plants and animals.)
Part II: Multiple Choice Questions
1) The term anaerobic means
A) without bacteria.
B) without CO2.
C) without ATP.
D) without O2
E) with O2.
2) How do cells capture the energy released by cellular respiration?
A) They store it in molecules of carbon dioxide.
B) They produce glucose.
C) The energy is coupled to oxygen.
D) They produce ATP.
E) None of the choices are correct.
3) Which one of the following is true?
A) Cellular respiration occurs in mitochondria and in chloroplasts.
B) Photosynthesis occurs in chloroplasts and cellular respiration occurs in mitochondria.
C) Photosynthesis occurs in mitochondria and in chloroplasts.
D) Photosynthesis occurs in mitochondria and cellular respiration occurs in chloroplasts.
E) Neither cellular respiration nor photosynthesis occurs in mitochondria and in chloroplasts.
4) Respiration _____, and cellular respiration ______.
A) uses glucose . . . produces glucose
B) produces glucose . . . produces oxygen
C) is gas exchange . . . produces ATP
D) produces ATP . . . is gas exchange
E) produces glucose . . . is gas exchange
5) Which of the following are products of cellular respiration?
A) energy to make ATP and carbon dioxide
B) glucose and carbon dioxide
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Biol 101
Exam 3: Energy, Photosynthesis & Respiration
Fall 2006
C) oxygen and energy to make ATP
D) oxgyen and carbon dioxide
E) oxygen and glucose
6) Which of the following statements is/are true about the energy yields from cellular respiration?
A) Cellular respiration is more efficient at harnessing energy from glucose than car engines are at
harnessing energy from gasoline.
B) Cellular respiration converts all of the energy in glucose into high-energy ATP bonds.
C) The heat produced during cellular respiration is only a tiny fraction of the chemical energy available in
a glucose molecule.
D) Cellular respiration converts the kinetic energy of glucose into chemical energy.
E) All of the choices are true.
7) Which one of the following statements is false? Cellular respiration
A) produces carbon dioxide.
B) is a single chemical reaction with just one step.
C) releases heat.
D) consumes glucose.
E) produces water.
8) The overall equation for the aerobic cellular respiration of glucose is
A) CO2 + H2O → C6H12O6 + O2 + ATP + Heat
B) C6H12O6 + O2 → CO2 + H2O + ATP + Heat
C) C6H12O6 → Lactic acid + ATP + Heat
D) C6H12O6  CO2 + Ethyl alcohol + ATP + Heat
9) During cellular respiration, the energy in glucose
A) is used to manufacture glucose.
B) is used to make ATP
C) becomes stored in molecules of ammonia.
D) makes carbon dioxide
10) During redox reactions
A) a substance that gains electrons is said to be oxidized.
B) electrons are lost from one substance and added to another substance.
C) the loss of electrons from one substance is called reduction.
D) protons from one molecule replace the electrons lost from another molecule.
E) None of the choices are correct.
11) Oxidation is the __________, and reduction is the __________.
A) gain of electrons . . . loss of electrons
B) loss of electrons . . . gain of electrons
C) gain of protons . . . loss of protons
D) gain of oxygen . . . loss of oxygen
E) loss of oxygen . . . gain of oxygen
12) In biological systems, an important enzyme involved in the regulation of redox reactions is
A) oxygen.
B) water.
C) dehydrogenase.
D) ATP.
E) glucose.
13) During cellular respiration, NADH
A) is chemically converted into ATP.
B) is converted to NAD+ by an enzyme called dehydrogenase.
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Biol 101
Exam 3: Energy, Photosynthesis & Respiration
Fall 2006
C) is reduced to form NAD+.
D) delivers its electron load to the first electron carrier molecule.
E) None of the choices are correct.
14) During cellular respiration, electrons move through a series of electron-carrier molecules. Which of
the following is a true statement about this process?
A) Molecular oxygen is eventually oxidized by the electrons to form water.
B) Electrons move from carriers that have more affinity for them to carriers that have less affinity for them.
C) Electrons release large amounts of energy each time they are transferred from one carrier to another.
D) The carrier molecules are found in the cytoplasm of eukaryotic and prokaryotic cells.
E) None of the statements are true.
15) Which one of the following is the correct sequence of stages in cellular respiration?
A) glycolysis, oxidative phosphorylation, and the citric acid cycle
B) glycolysis, the citric acid cycle, and oxidative phosphorylation
C) the citric acid cycle, oxidative phosphorylation, and glycolysis
D) oxidative phosphorylation, the citric acid cycle, and glycolysis
E) oxidative phosphorylation, glycolysis, and the citric acid cycle
16) A drug is tested in the laboratory and is found to create holes in both mitochondrial membranes.
Scientists suspect that the drug will be harmful to human cells because it will inhibit
A) glycolysis.
B) the citric acid cycle.
C) oxidative phosphorylation.
D) the formation of alcohol.
E) the citric acid cycle and oxidative phosphorylation.
17) During which phase of cellular respiration does substrate-level phosphorylation take place?
A) the citric acid cycle
B) "grooming" of pyruvic acid
C) glycolysis
D) oxidative phosphorylation
E) glycolysis and the citric acid cycle
18) Which one of the following metabolic pathways is common in aerobic and anaerobic organisms?
A) oxidative phosphorylation
B) chemiosmosis
C) glycolysis
D) the citric acid cycle
E) None of the choices are correct.
19) Which of the following is a result of glycolysis?
A) a net loss of two ATPs per glucose molecule
B) conversion of FAD to FADH2
C) conversion of glucose to two three-carbon compounds
D) production of CO2
E) conversion of NADH to NAD+
20) Glycolysis
A) does not occur in bacterial cells.
B) takes place in virtually all cells.
C) does not occur in yeast cells.
D) does not occur in animal cells.
E) does not occur in plant cells.
21) Pyruvate
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Biol 101
Exam 3: Energy, Photosynthesis & Respiration
Fall 2006
A) is the molecule that starts the citric acid cycle.
B) is the end product of oxidative phosphorylation.
C) is a six-carbon molecule.
D) is the end product of chemiosmosis.
E) forms at the end of glycolysis.
22) Between glycolysis and the citric acid cycle,
A) pyruvate is oxidized while a molecule of NAD+ is reduced to NADH.
B) coenzyme A is cleaved off of the four-carbon compound.
C) a carbon atom is added to make a four-carbon compound.
D) More than one of the choices is correct.
E) None of the choices are correct.
23) During cellular respiration, glucose is converted into two pyruvic acid molecules. These molecules
A) together contain less chemical energy than was found in the original glucose molecule.
B) are oxidized.
C) each lose a carbon atom, which is released as CO 2) ) .
D) are each converted into a two-carbon molecule joined to a coenzyme A molecule.
E) All of the choices are correct.
24) The end products of the citric acid cycle include all of the following except
A) CO2.
B) NADH.
C) pyruvic acid.
D) FADH2.
E) ATP.
25) At the end of the citric acid cycle, most of the energy remaining from the original glucose is stored in
A) FADH2
B) CO2.
C) pyruvic acid.
D) ATP.
E) NADH.
26) In the electron transport chain, the final electron acceptor is
A) a molecule of water.
B) a molecule of carbon dioxide.
C) ATP.
D) ADP.
E) an oxygen atom.
27) Rotenone is a poison commonly added to insecticides. Insects exposed to rotenone will die because
A) high levels of fermentation products will build up.
B) water will not be produced and dehydration will occur.
C) anaerobic respiration can't occur.
D) of inadequate ATP production.
E) None of the choices are correct.
28) Cyanide differs from dinitrophenol because cyanide
A) is an electron transport blocker and dinitrophenol is a reaction uncoupler.
B) makes the membrane of mitochondria leaky to H+ ions and prevents a concentration gradient from
building up; dinitrophenol blocks the passage of electrons through electron carriers.
C) inhibits the production of ATP by inhibiting ATP synthase; dinitrophenol causes mitochondrial
membranes to become less permeable to H+ ions.
D) is highly toxic to human cells and dinitrophenol is nontoxic.
E) None of the choices are correct.
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Biol 101
Exam 3: Energy, Photosynthesis & Respiration
Fall 2006
29) Which of the following statements about the energy yield of aerobic respiration is false?
A) Most of the ATP derived during aerobic respiration results from oxidative phosphorylation.
B) Oxidative phosphorylation resulting from one glucose molecule may yield 32-34 ATP molecules.
C) Less than 50% of the chemical energy available in glucose is converted to ATP energy.
D) Glycolysis and the "grooming" of pyruvate together produce more NADH per glucose molecule than
does the citric acid cycle.
E) Each FADH2 molecule yields 2 ATP molecules and each NADH molecule generates 3 ATP molecules.
30) The energy yield from the complete aerobic breakdown of a single molecule of glucose
A) is less than the yield from anaerobic respiration.
B) increases as the supply of oxygen increases.
C) is always 38 ATP.
D) can vary with the mechanism used to shuttle NADH electrons into the mitochondrion.
E) is equivalent to the yield from alcoholic fermentation.
31) During chemiosmosis
A) a concentration gradient is generated when large numbers of H+ ions are passively transported from
the matrix of the mitochondrion to the mitochondrion's intermembrane space.
B) energy is generated by coupling exergonic reactions with other exergonic reactions.
C) ATP is synthesized when H+ ions move through a protein port provided by ATP synthase.
D) H+ ions serve as the final electron acceptor.
E) energy is released as H+ ions move freely across mitochondrial membranes.
32) Which of the following processes produces the most ATP per molecule of glucose oxidized?
A) aerobic respiration
B) alcoholic fermentation
C) lactic acid fermentation
D) anaerobic respiration
E) All produce approximately the same amount of ATP per molecule of glucose.
33) Muscle soreness associated with strenuous exercise is at least partly due to
A) the presence of lactic acid produced during fermentation in muscle cells.
B) the large amount of carbon dioxide that builds up in the muscle.
C) the accumulation of alcohol from anaerobic respiration.
D) an excess of ATP that builds up during vigorous exercise.
E) None of the choices are correct.
34) In yeast cells,
A) alcohol is produced after glycolysis.
B) glucose is produced during photosynthesis.
C) lactic acid is produced during glycolysis.
D) alcohol is produced during the citric acid cycle.
E) lactic acid is produced during anaerobic respiration.
35) When proteins are used as a source of energy for the body, the proteins
A) are hydrolyzed to fatty acids and converted to acetyl CoA, which enters the citric acid cycle.
B) are converted mainly into intermediates of glycolysis or the citric acid cycle.
C) are hydrolyzed to glycerols and then converted to glyceraldehyde 3-phosphate, which is fed into
glycolysis.
D) are hydrolyzed to their constituent amino acids; electrons are stripped from the amino acids and
passed to the electron transport chain.
E) are converted into glucose molecules, which are fed into glycolysis.
36) When a fatty acid is used for aerobic respiration, it first hydrolyzes fats to
A) glycerol and fatty acids.
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Biol 101
Exam 3: Energy, Photosynthesis & Respiration
Fall 2006
B) sugars and glycerol.
C) glycerol and amino acids.
D) sugars and amino acids.
E) fatty acids and sugars.
37) The conversion of CO2 and H2O into organic compounds using energy from light is called
A) photorespiration.
B) glycolysis.
C) photosynthesis.
D) fermentation.
E) cellular respiration.
38) By-products of cellular respiration include
A) carbon dioxide and water.
B) carbon dioxide and ATP.
C) oxygen and heat.
D) NADH and ATP.
E) FADH2 and NADH.
39) The summary equation for photosynthesis is
A) CO2 + H2O → C6H12O6 + O2 + ATP + Heat
B) C6H12O6 + O2 → CO2 + H2O + ATP + Heat
C) CO2 + H2O → C6H12O6 + O2
D) C6H12O6  CO2 + Ethyl alcohol + ATP + Heat
40) Which one of the following statements is false?
A) Burning fossil fuels releases carbon dioxide that was removed from the atmosphere millions of years
ago.
B) Willows pack more fuel and power than most native trees.
C) Plants require carbon dioxide, water, and sunlight to make glucose.
D) All of the food for people can be traced back to photosynthetic plants.
E) Burning wood contributes more to acid rain than burning fossil fuels.
41) Photoautotrophs
A) produce organic molecules from inorganic molecules.
B) make sugar by using organic raw materials.
C) include only the green plants.
D) eat other organisms that use light energy to make food molecules.
E) None of the choices are correct.
42) Which of the following is not an example of a photoautotroph?
A) algae
B) kelp in an underwater forest
C) cyanobacteria in freshwater and marine ecosystems
D) herbs like thyme and basil
E) fungi
43) Autotrophs that utilize light as their energy source are
A) fungi.
B) photoautotrophs.
C) chemosynthetic autotrophs.
D) consumers.
E) heterotrophs.
44) Producers
A) sustain themselves without eating.
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Biol 101
Exam 3: Energy, Photosynthesis & Respiration
Fall 2006
B) make organic food molecules from simple raw materials.
C) manufacture the biosphere's food supply.
D) are autotrophs.
E) All of the choices are correct.
45) Chloroplasts contain disklike membranous sacs arranged in stacks called
A) cristae.
B) thylakoids.
C) vacuoles.
D) stroma.
E) grana.
46) The oxygen released into the air as a product of photosynthesis comes from
B) chlorophyll.
C) carbon dioxide.
D) water.
E) None of the choices are correct.
47) In the chloroplast, sugars are made in a compartment that is filled with a thick fluid called the
A) matrix.
B) mesophyll.
C) stomata.
D) thylakoid.
E) stroma.
48) Where is chlorophyll found in a plant cell?
A) cytoplasm
B) thylakoid membranes
C) stroma
D) matrix
E) cristae
49) Which of the following is true concerning the role of redox reactions in photosynthesis and cellular
respiration?
A) In photosynthesis, carbon dioxide is oxidized to form sugar while in respiration, sugar is reduced to
form carbon dioxide.
B) Photosynthesis involves only oxidations while respiration involves only reductions.
C) Photosynthesis involves only reductions while respiration involves only oxidations.
D) In photosynthesis, carbon dioxide is reduced to form sugar while in respiration, sugar is oxidized to
form carbon dioxide.
E) None of the choices are true.
50) What is the source of energy that provides the boost for electrons during photosynthesis?
A) ATP
B) light
C) cellular respiration
D) electromagnetism
E) None of the choices are correct.
51) The light reactions occur in the _____ while the Calvin cycle occurs in the ______
A) stroma . . . thylakoid membranes
B) cytoplasm . . . stroma
C) thylakoid membranes . . . stroma
D) cytoplasm . . . thylakoid membrane
E) stroma . . . nucleus
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Biol 101
Exam 3: Energy, Photosynthesis & Respiration
Fall 2006
52) Which of the following are produced during the light reactions of photosynthesis?
A) ADP, NADP+, O2
B) glucose, ADP, NAD+
C) ATP, NADPH, CO2
D) glucose, ADP, NADP+, CO2
E) ATP, NADPH, O2
53) Which of the following are produced during the Calvin cycle?
A) glucose, ADP, NADP+
B) ATP, NADPH, O2
C) ATP, NADPH, CO2
D) glucose, ADP, NADP+, CO2
E) ADP, NADP+ , O2
54) Carbon fixation
A) occurs when carbon and oxygen from CO2 are incorporated into an organic molecule.
B) powers the process of glucose synthesis by supplying the cell with ATP.
C) occurs during the light reactions.
D) uses noncyclic electron flow to capture energy in glucose.
E) provides the cell with a supply of NADPH molecules.
55) The Calvin cycle involves all of the following except:
A) addition of electrons and protons to carbon.
B) formation of waste products in the form of CO2
C) reduction of carbon.
D) carbon fixation.
E) regeneration of NADP+.
56) Sunlight is a type of __________ energy.
A) potential
B) kinetic
C) nuclear
D) stored
E) electromagnetic
57) Why are (most) plants green?
A) Chlorophyll a reflects green light.
B) Chlorophyll b primarily uses green light as the source of energy for photosynthesis.
C) Green helps plants blend into their environment as a sort of camouflage.
D) Chlorophyll a absorbs green light.
E) All photosynthetic pigments are colored green.
58) Of the following wavelengths of light, which would you expect to be least absorbed by chlorophyll a?
A) blue
B) yellow
C) green
D) red
59) When a pigment molecule absorbs a photon, one of its electrons____
A) gains energy.
B) becomes excited.
C) is put into an unstable state.
D) is raised from the ground state.
E) All of the choices are correct.
60) Clusters of light-gathering antenna pigments in a photosystem__
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Biol 101
Exam 3: Energy, Photosynthesis & Respiration
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A) absorb electrons.
B) do not absorb photons.
C) pass energy to the reaction center.
D) are found in the roots of plants.
E) break down H2O.
61) In a photosystem, clusters of chlorophyll a, chlorophyll b, and carotenoid pigments function most like
A) an electrical generator.
B) a propeller on a motorboat.
C) a windmill.
D) an antenna.
E) a spring.
62) As a result of the cascade of electrons down the electron transport chains of the light reactions,
A) NADPH is reduced to NADP+
B) NADP+is oxidized to NADPH.
C) water is formed.
D) NADPH is oxidized to NADP+
E) NADP+ is reduced to NADPH.
63) The electrons lost from the reaction center of photosystem I are replaced by electrons from
A) ATP.
B) CO2
C) H2O
D) the top of the electron transport chain.
E) the bottom of the electron transport chain.
64) In photosynthesis, the chemiosmotic production of ATP
A) requires oxygen.
B) is analogous to the production of ATP in mitochondria.
C) requires the input of NADPH.
D) is done by the Calvin cycle.
E) All of the choices are correct.
65) Mitochondria transfer ___ energy from ___ to ATP; chloroplasts transform ___ energy into the
chemical energy of ATP.
A) food . . . light . . . chemical
B) food . . . light . . . nuclear
C) chemical . . . food . . . light
D) nuclear . . . light . . . food
E) light . . . food . . . kinetic
66) Photosynthetic organisms derive their carbon from
A) hydrocarbons.
B) carbon monoxide.
C) methane.
D) carbon dioxide.
67) ATP and NADPH
A) play a role in glucose synthesis by plants.
B) are inputs to the photosystems.
C) production is associated with events taking place on the inner mitochondrial membrane.
D) are products of the Calvin cycle.
E) All of the choices are correct.
68) The ultimate source of all the food we eat and the oxygen we breathe is
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Biol 101
Exam 3: Energy, Photosynthesis & Respiration
Fall 2006
A) photosynthesis.
B) anaerobic metabolism.
C) chemiosmosis.
D) glycolysis.
E) cellular respiration.
69) The electrons lost from the reaction center of photosystem II are replaced by electrons from
A) CO2
B) NADPH.
C) photosystem I.
D) H2O.
E) ATP.
70) Photosystem II
A) does not have a reaction center.
B) is reduced by NADPH.
C) passes electrons to photosystem I.
D) has P700 at its reaction center.
E) All of the choices are correct.
71) Photophosphorylation differs from oxidative phosphorylation in that
A) regeneration of ATP is driven by a flow of protons through an ATP synthase.
B) the final electron acceptor is NADP+ and not oxygen.
C) it involves an electron transport chain.
D) energy is stored in the form of a proton concentration difference.
E) its enzymes are membrane-bound.
72) In photophosphorylation, energy from electron flow is used to transport ______ from the ______to the
thylakoid compartment, generating a concentration gradient of __________.
A) H+. . . grana . . . electrons
B) electrons . . . stroma . . . H+
C) H+. . . stroma . . . ATP
D) H+ to power of ((+) ) . . . stroma . . . H+
E) electrons . . . grana . . . H+
73) Plant cells
A) lack mitochondria and chloroplasts.
B) have mitochondria and chloroplasts.
C) have mitochondria but do not have chloroplasts.
D) lack mitochondria but have chloroplasts.
74) What is the main advantage of the C4 and CAM photosynthesis strategies over the C3 strategy?
A) They allow the plant to avoid photorespiration by producing a four-carbon sugar in place of glucose.
B) They make it possible for the plant to use the Calvin cycle at night and during the day.
C) They allow the plant to fix carbon more efficiently under conditions of low atmospheric CO2
D) They help the plant conserve water and synthesize glucose efficiently under hot, dry conditions.
E) They allow the plant to fix carbon more efficiently in dim or cool conditions.
75) Do photosynthesizing plants have mitochondria?
A) Yes, to convert glucose into starch.
B) Yes, but only in CAM plants, in which carbon is fixed at night.
C) No, chloroplasts produce ATP and glucose.
D) Yes, to supply the plant with the ATP needed to power various cell activities.
E) Yes, but they are used mainly to produce certain Krebs cycle intermediates, which are needed for the
synthesis of compounds such as amino acids.
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Biol 101
Exam 3: Energy, Photosynthesis & Respiration
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Fall 2006