AP Bio Photosynthesis & Respiration
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____
____
____
____
____
____
1. What is the term used for the metabolic pathway in which glucose (C6H12O6) is degraded to carbon dioxide
(CO2) and water?
a. cellular respiration
b. glycolysis
c. fermentation
d. citric acid cycle
e. oxidative phosphorylation
2. Which of the following statements is (are) correct about an oxidation-reduction (or redox) reaction?
a. The molecule that is reduced gains electrons.
b. The molecule that is oxidized loses electrons.
c. The molecule that is reduced loses electrons.
d. The molecule that is oxidized gains electrons.
e. Both A and B are correct.
3. Where does glycolysis takes place?
a. mitochondrial matrix
b. mitochondrial outer membrane
c. mitochondrial inner membrane
d. mitochondrial intermembrane space
e. cytosol
4. The ATP made during glycolysis is generated by
a. substrate-level phosphorylation.
b. electron transport.
c. photophosphorylation.
d. chemiosmosis.
e. oxidation of NADH to NAD+.
5. The oxygen consumed during cellular respiration is involved directly in which process or event?
a. glycolysis
b. accepting electrons at the end of the electron transport chain
c. the citric acid cycle
d. the oxidation of pyruvate to acetyl CoA
e. the phosphorylation of ADP to form ATP
6. Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent?
a. electron transport
b. glycolysis
c. the citric acid cycle
d. oxidative phosphorylation
e. chemiosmosis
The figure below illustrates some of the steps (reactions) of glycolysis in their proper sequence. Each step is
lettered. Use these letters to answer the following questions.
____
____
____
____
____
7. Which step shows a split of one molecule into two smaller molecules?
a. A
b. B
c. C
d. D
e. E
8. In which step is an inorganic phosphate added to the reactant?
a. A
b. B
c. C
d. D
e. E
9. Which step consists of a phosphorylation reaction in which ATP is the phosphate source?
a. A
b. B
c. C
d. D
e. E
10. In addition to ATP, what are the end products of glycolysis?
a. CO2 and H2O
b. CO2 and pyruvate
c. NADH and pyruvate
d. CO2 and NADH
e. H2O, FADH2, and citrate
11. A molecule that is phosphorylated
a. has an increased chemical reactivity; it is primed to do cellular work.
b. has a decreased chemical reactivity; it is less likely to provide energy for cellular work.
c. has been oxidized as a result of a redox reaction involving the gain of an inorganic
phosphate.
d. has been reduced as a result of a redox reaction involving the loss of an inorganic
phosphate.
e. has less energy than before its phosphorylation and therefore less energy for cellular work.
____ 12. All of the following are functions of the citric acid cycle except
a. production of ATP.
b. production of NADH.
c. production of FADH2.
d. release of carbon dioxide.
e. adding electrons and protons to oxygen, forming water.
Refer to the figure below, showing the citric acid cycle, as a guide to answer the following questions.
____ 13. Starting with one molecule of isocitrate and ending with fumarate, what is the maximum number of ATP
molecules that could be made through substrate-level phosphorylation?
a. 1
b. 2
c. 11
d. 12
e. 24
____ 14. How many molecules of carbon dioxide (CO2) would be produced by five turns of the citric acid cycle?
a. 2
b. 5
c. 10
d. 12
e. 60
____ 15. Cellular respiration harvests the most chemical energy from which of the following?
a. substrate-level phosphorylation
b. chemiosmotic phosphorylation
c. converting oxygen to ATP
d. transferring electrons from organic molecules to pyruvate
e. generating carbon dioxide and oxygen in the electron transport chain
____ 16. During aerobic respiration, electrons travel downhill in which sequence?
a. food
citric acid cycle
ATP
NAD+
b. food
NADH
electron transport chain
oxygen
____ 17.
____ 18.
____ 19.
____ 20.
____ 21.
____ 22.
____ 23.
c. glucose
pyruvate
ATP
oxygen
d. glucose
ATP
electron transport chain
NADH
e. food
glycolysis
citric acid cycle
NADH
ATP
Where are the proteins of the electron transport chain located?
a. cytosol
b. mitochondrial outer membrane
c. mitochondrial inner membrane
d. mitochondrial intermembrane space
e. mitochondrial matrix
The primary role of oxygen in cellular respiration is to
a. yield energy in the form of ATP as it is passed down the respiratory chain.
b. act as an acceptor for electrons and hydrogen, forming water.
c. combine with carbon, forming CO2.
d. combine with lactate, forming pyruvate.
e. catalyze the reactions of glycolysis.
Inside an active mitochondrion, most electrons follow which pathway?
a. glycolysis
NADH
oxidative phosphorylation
ATP
oxygen
b. citric acid cycle
FADH2
electron transport chain
ATP
c. electron transport chain
citric acid cycle ATP
oxygen
d. pyruvate
citric acid cycle
ATP
NADH
oxygen
e. citric acid cycle
NADH
electron transport chain
oxygen
During oxidative phosphorylation, H2O is formed. Where does the oxygen for the synthesis of the water come
from?
a. carbon dioxide (CO2)
b. glucose (C6H12O6)
c. molecular oxygen (O2)
d. pyruvate (C3H3O3–)
e. lactate (C3H5O3–-)
In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to
ATP?
a. energy released as electrons flow through the electron transport system
b. energy released from substrate-level phosphorylation
c. energy released from ATP synthase pumping hydrogen ions against their concentration
gradient
d. energy released from movement of protons through ATP synthase
e. No external source of energy is required because the reaction is exergonic.
Energy released by the electron transport chain is used to pump H+ ions into which location?
a. cytosol
b. mitochondrial outer membrane
c. mitochondrial inner membrane
d. mitochondrial intermembrane space
e. mitochondrial matrix
During aerobic cellular respiration, a proton gradient in mitochondria is generated by ____ and used primarily
for ____.
a. the electron transport chain; ATP synthesis
b. the electron transport chain; substrate-level phosphorylation
c. glycolysis; production of H2O
d. fermentation; NAD+ reduction
e. diffusion of protons; ATP synthesis
____ 24. The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is
a. oxidation of glucose to CO2 and water.
b. the thermodynamically favorable flow of electrons from NADH to the mitochondrial
electron transport carriers.
c. the final transfer of electrons to oxygen.
d. the difference in H+ concentrations on opposite sides of the inner mitochondrial
membrane.
e. the thermodynamically favorable transfer of phosphate from glycolysis and the citric acid
cycle intermediate molecules of ADP.
____ 25. Where is ATP synthase located in the mitochondrion?
a. cytosol
b. electron transport chain
c. outer membrane
d. inner membrane
e. mitochondrial matrix
____ 26. In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of
a. ATP, CO2and ethanol (ethyl alcohol).
b. ATP, CO2, and lactate.
c. ATP, NADH, and pyruvate.
d. ATP, pyruvate, and oxygen.
e. ATP, pyruvate, and acetyl CoA.
____ 27. You have a friend who lost 7 kg (about 15 pounds) of fat on a "low carb" diet. How did the fat leave her
body?
a. It was released as CO2 and H2O.
b. Chemical energy was converted to heat and then released.
c. It was converted to ATP, which weighs much less than fat.
d. It was broken down to amino acids and eliminated from the body.
e. It was converted to urine and eliminated from the body.
____ 28. Organisms that can exist with light as an energy source and an inorganic form of carbon and other raw
materials
a. are called photoautotrophs.
b. do not exist in nature.
c. are called heterotrophs.
d. are best classified as decomposers.
e. both C and D
____ 29. Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin
cycle?
a. CO2 and glucose
b. H2O and O2
c. ADP, Pi, and NADP+
d. electrons and H+
e. ATP and NADPH
____ 30. What is the primary function of the light reactions of photosynthesis?
a. to produce energy-rich glucose from carbon dioxide and water
b. to produce ATP and NADPH
c. to produce NADPH used in respiration
d. to convert light energy to the chemical energy of PGAL
e. to use ATP to make glucose
____ 31. Where does the Calvin cycle take place?
____ 32.
____ 33.
____ 34.
____ 35.
____ 36.
____ 37.
____ 38.
a. stroma of the chloroplast
b. thylakoid membrane
c. cytoplasm surrounding the chloroplast
d. chlorophyll molecule
e. outer membrane of the chloroplast
A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What
wavelengths of visible light are not being absorbed by this pigment?
a. red and yellow
b. blue and violet
c. green and yellow
d. blue, green, and red
e. green, blue, and violet
In the thylakoid membranes, what is the main role of the antenna pigment molecules?
a. split water and release oxygen to the reaction-center chlorophyll
b. harvest photons and transfer light energy to the reaction-center chlorophyll
c. synthesize ATP from ADP and Pi
d. transfer electrons to ferredoxin and then NADPH
e. concentrate photons within the stroma
Which of the following statements about the light reactions of photosynthesis are true?
a. The splitting of water molecules provides a source of electrons.
b. Chlorophyll (and other pigments) absorb light energy, which excites electrons.
c. ATP is generated by photophosphorylation.
d. Only A and C are true.
e. A, B, and C are true.
What does cyclic electron flow in the chloroplast produce?
a. ATP
b. NADPH
c. glucose
d. A and B
e. A, B, and C
Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the
stroma. This damage will have the most direct effect on which of the following processes?
a. the splitting of water
b. the absorption of light energy by chlorophyll
c. the flow of electrons from photosystem II to photosystem I
d. the synthesis of ATP
e. the reduction of NADP+
What does the chemiosmotic process in chloroplasts involve?
a. establishment of a proton gradient
b. diffusion of electrons through the thylakoid membrane
c. reduction of water to produce ATP energy
d. movement of water by osmosis into the thylakoid space from the stroma
e. formation of glucose, using carbon dioxide, NADPH, and ATP
In a plant cell, where are the ATP synthase complexes located?
a. thylakoid membrane
b. plasma membrane
c. inner mitochondrial membrane
d. A and C
e. A, B, and C
____ 39. In mitochondria, chemiosmosis translocates protons from the matrix into the intermembrane space, whereas
in chloroplasts, chemiosmosis translocates protons from
a. the stroma to the photosystem II.
b. the matrix to the stroma.
c. the stroma to the thylakoid space.
d. the intermembrane space to the matrix.
e. ATP synthase to NADP+ reductase.
____ 40. Which of the following statements best describes the relationship between photosynthesis and respiration?
a. Respiration is the reversal of the biochemical pathways of photosynthesis.
b. Photosynthesis stores energy in complex organic molecules, while respiration releases it.
c. Photosynthesis occurs only in plants and respiration occurs only in animals.
d. ATP molecules are produced in photosynthesis and used up in respiration.
e. Respiration is anabolic and photosynthesis is catabolic.
____ 41. Of the following, what do both mitochondria and chloroplasts have in common?
a. thylakoid membranes
b. chemiosmosis
c. ATP synthase
d. B and C only
e. A, B, and C
Refer to the choices to answer the following questions. Each choice may be used once, more than once, or not
at all. Indicate whether the following events occur during
A.
B.
C.
D.
photosynthesis
respiration
both photosynthesis and respiration
neither photosynthesis nor respiration
____ 42. synthesis of ATP by the chemiosmotic mechanism
a. A
b. B
c. C
d. D
____ 43. reduction of oxygen which forms water
a. A
b. B
c. C
d. D
____ 44. Where do the enzymatic reactions of the Calvin cycle take place?
a. stroma of the chloroplast
b. thylakoid membranes
c. outer membrane of the chloroplast
d. electron transport chain
e. thylakoid space
____ 45. What is the primary function of the Calvin cycle?
a. use ATP to release carbon dioxide
b. use NADPH to release carbon dioxide
c. split water and release oxygen
d. transport RuBP out of the chloroplast
e. synthesize simple sugars from carbon dioxide
Use the figure below to answer the following statements.
____ 46. Which of the following statements is true concerning the figure?
a. It represents cell processes involved in C4 photosynthesis.
b. It represents the type of cell structures found in CAM plants.
c. It represents an adaptation that minimizes photorespiration.
d. A and C are true.
e. A, B, and C are true.
____ 47. Oxygen would inhibit the CO2 fixation reactions in
a. cell I only.
b. cell II only.
c. neither cell I nor cell II.
d. both cell I and cell II.
e. cell I during the night and cell II during the day.
____ 48. In which cell would you expect photorespiration?
a. Cell I
b. Cell II
c. Cell I at night
d. Cell II at night
e. neither Cell I nor Cell II
____ 49. CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they
a. fix CO2 into organic acids during the night.
b. fix CO2 into sugars in the bundle-sheath cells.
c. fix CO2 into pyruvate in the mesophyll cells.
d. use the enzyme phosphofructokinase, which outcompetes rubisco for CO2.
e. use photosystems I and II at night.
____ 50. Photorespiration lowers the efficiency of photosynthesis by preventing the formation of
a. carbon dioxide molecules.
b. 3-phosphoglycerate molecules
c. ATP molecules.
d. ribulose bisphosphate molecules.
e. RuBP carboxylase molecules.
AP Bio Photosynthesis & Respiration
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
A
E
E
A
B
B
B
C
A
C
A
E
A
C
B
B
C
B
E
C
D
D
A
D
D
A
A
A
E
B
A
A
B
E
A
D
A
D
C
B
D
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
42.
43.
44.
45.
46.
47.
48.
49.
50.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
C
B
A
E
D
B
B
A
B
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
1
1