NEETBotanyPhotosynthesis in Higher Plants
During a specific light reaction process in chloroplasts, an excited electron is not transferred to NADP ^+ but cycles back to the reaction centre complex via the electron transport chain. Which of the following statements is correct regarding this specific event?
Options
- AIt requires the splitting of water to supply continuous electrons.
- BIt occurs in membrane regions that lack the NADP reductase enzyme.
- CIt occurs primarily in grana lamellae where both photosystems are functional.
- DIt results in the simultaneous synthesis of both ATP and NADPH + H ^+ .
Correct answer
B. It occurs in membrane regions that lack the NADP reductase enzyme.
Step-by-step solution
The process described in the question is cyclic photophosphorylation, where the electron is circulated within Photosystem I (PS I). This process occurs in the stroma lamellae, which lack both PS II and the NADP reductase enzyme. Because it lacks PS II, there is no photolysis (splitting) of water. The cyclic flow of electrons results only in the synthesis of ATP, not NADPH + H ^+ . Therefore, the correct statement is that it occurs in membrane regions lacking the NADP reductase enzyme. Answer: It occurs in membrane