Biochemistry Multiple Choice Questions on “ATP Synthesis by Photophosphorylation”.
1. If 8 photons are required to produce one molecule of O2, how many photons are required to produce one molecule of glucose?
A. 6
B. 8
C. 48
D. 12
Answer: C
Clarification: 6 molecules of O2 must be produced during the production of glucose, so 6×8=48 photons are required for producing one molecule of glucose.
2. When compared to retinal, chlorophyll can be described as a pigment that has a ____________
A. Narrow absorption range but high efficiency
B. Narrow absorption range but low efficiency
C. Wide absorption range but high efficiency
D. Wide absorption range but low efficiency
Answer: A
Clarification: Chlorophyll has a narrow absorption range but high efficiency compared to retinal.
3. Which of the following is the correct sequence for the movement of electrons during the light-dependent reactions of plants?
A. P700, P680, NADP+, water
B. P680, water, P700, NADP+
C. Water, P700, NADP+, P680
D. Water, P680, P700, NADP+
Answer: D
Clarification: The sequence for the movement of electrons firstly includes water, secondly P680 then P700 and finally NADP+.
4. Which pigment is used in human vision?
A. Retinal
B. Vitamin A
C. Ferredoxin
D. Beta-carotene
Answer: A
Clarification: Retinal is used in human vision.
5. Why light is required for light dependent reactions?
A. It splits ATP molecules which generates the energy necessary to power the light independent reactions
B. It is the source for electrons
C. It splits the water molecules
D. It energizes electrons in the reaction center
Answer: D
Clarification: Light energizes electrons in the reaction center, so it is required for light dependent reactions.
6. Photosynthesis takes place in sac like membranes called ___________
A. Thylakoids
B. Grana
C. Photosystems
D. Photons
Answer: A
Clarification: Photosynthesis takes place in thylakoid structures.
7. The carbon-assimilation reactions require ATP and NADPH in the ratio ___________
A. 3:2
B. 2:3
C. 3:4
D. 4:3
Answer: A
Clarification: The carbon-assimilation reactions require ATP and NADPH in the ratio 3:2.
8. Which of the following systems has an associated water splitting activity resembling that of plants?
A. Photosystem
B. Photosystem I
C. Photosystem II
D. Photosystem III
Answer: C
Clarification: Photosystem II has an associated water splitting activity resembling that of plants.
9. The earliest photo synthesizers used which of the following as the source of hydrogen?
A. CO2
B. C6H12O6
C. H2O
D. H2S
Answer: D
Clarification: The earliest photo synthesizers used H2S as the source of hydrogen.
10. Photosystem I used which of the following in its photo-center?
A. P700
B. P800
C. P900
D. P600
Answer: A
Clarification: Photosystem I used P700 in its photo-center.
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