Question

The final acceptor of e\(^{-}\) (electrons) during non-cyclic photophosphorylation is:

• A. NADP
• B. NADPH\(_2\)
• C. NADP\(^+\)
• D. H\(_2\)O

Hint:

In non-cyclic photophosphorylation, NADP\(^+\) is the final electron acceptor, which is reduced to NADPH and used in the Calvin cycle.

Answer 1

The Correct Option is C

In non-cyclic photophosphorylation, which is part of the light reactions in photosynthesis, the final electron acceptor is NADP\(^+\). Here’s how the process works:
- During the light reactions, chlorophyll absorbs light energy, exciting electrons.
- These excited electrons travel through the electron transport chain and are ultimately transferred to NADP\(^+\), reducing it to NADPH (NADP\(^+\) + e\(^{-}\) + H\(^+\) → NADPH).
- The NADPH produced is then used in the Calvin cycle for the reduction of carbon dioxide. The other options are incorrect because:
- NADP refers to the oxidized form, which is the electron acceptor.
- NADPH\(_2\) does not exist as a stable molecule; the correct reduced form is NADPH.
- H\(_2\)O is the molecule split during photolysis in the light reactions, providing electrons to replace those lost by chlorophyll, but it is not the electron acceptor. Thus, the correct answer is NADP\(^+\).