Answer: Reduces NADP+ to NADPH using electrons from ferredoxin.
- A Splits water molecules at the manganese cluster of Photosystem II
- B Reduces NADP+ to NADPH using electrons from ferredoxin
- C Actively pumps protons across the thylakoid membrane into the lumen
- D Catalyzes phosphorylation of ADP to ATP at the F<sub>1</sub> head of ATP synthase
Correct answer: B. Reduces NADP+ to NADPH using electrons from ferredoxin
Explanation: FNR: enzyme that accepts 2 electrons from 2 reduced ferredoxin molecules and transfers them to NADP+, reducing it to NADPH (final electron acceptor of the light reactions).
Simplified photosynthesis diagram: light energy, CO2, and H2O enter the leaf and are converted in the chloroplast into glucose and O2.
Concept context
Light reactions, the Calvin cycle, C 3 /C 4 /CAM pathways, photorespiration, and factors affecting the rate of photosynthesis. One of the highest-yield NEET chapters.