This set of Biochemistry Multiple Choice Questions & Answers (MCQs) focuses on “General Features of Photophosphorylation”.
1. Which of the following statements about thylakoids is false?
a) They contain chlorophyll pigments
b) They contain the photosystems
c) They contain Calvin cycle enzymes
d) They contain the electron transport machinery
Explanation: Chloroplast stroma contains Calvin cycle enzymes and intermediates.
2. One of the following is the source of electrons in photosynthesis
Explanation: Water is the source of electrons in photosynthesis. These electrons are required to reduce oxidized chlorophyll a molecules.
3. Which of the following about Calvin cycle is correct?
a) It is a metabolic pathway by which plants convert CO2 into pentose sugars as the main product
b) With decrease in light intensity, the enzymes are more reactive
c) Rubisco adds CO2 to 3-phosphoglycerate
d) It is a metabolic pathway by which plants convert CO2 and water into carbohydrates
Explanation: CO2 combines with ribulose 1, 5-bisphosphate.
The enzymes are more reactive if there is an increase in light intensity.
4. Favorable conditions for cyclic photophosphorylation are
a) Aerobic and optimum light
b) Aerobic condition only
c) Aerobic and low light intensity
d) Anaerobic and low light intensity
Explanation: Favorable conditions for cyclic photophosphorylation are aerobic and optimum light.
5. Hydrogen is transferred from the light reaction to the dark reaction in photosynthesis by
Explanation: Diphosphopyridine nucleotide transfers hydrogen from the light reaction to the dark reaction in photosynthesis.
6. Calvin cycle occurs in
d) Golgi body
Explanation: Calvin cycle occurs in cytoplasm.
7. Light energy is converted to chemical energy in the presence of
Explanation: Photosynthetic pigment chlorophyll captures the energy from sunlight and converts it and stores it in energy-storage molecules ATP and NADPH.
8. Photosynthesis can be described as
a) Reductive, anabolic, endergonic process
b) Reductive, anabolic, exergonic process
c) Oxidative, anabolic, endergonic process
d) Oxidative, catabolic, exergonic process
Explanation: Photosynthesis involves gaining of electrons; producing complex substances from simpler ones and requires energy.
9. The first person to study the influence of light during photosynthesis is
b) Van Niel
c) J. Ingenhouz
Explanation: Jan Ingenhouz was the best known to show that light is essential for photosynthesis.
10. The percentage of light energy fixed in photosynthesis is around
Explanation: Around 1% of light energy is fixed in photosynthesis.
Sanfoundry Global Education & Learning Series – Biochemistry.
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