Non-cyclic photophosphorylation is performed by

Options

A. Dark reaction
B. `PS` I
C. `PS` II
D. Both B and C.

Answer

**Step-by-Step Solution:**

1. **Understanding Non-Cyclic Photophosphorylation:**
Non-cyclic photophosphorylation is a process that occurs during the light-dependent reactions of photosynthesis. It involves the conversion of light energy into chemical energy in the form of ATP and NADPH.

2. **Role of Photosystems:**
There are two main photosystems involved in this process: Photosystem I (PSI) and Photosystem II (PSII). Both systems play a crucial role in capturing light energy.

3. **Photolysis of Water:**
In non-cyclic photophosphorylation, water molecules are split (a process called photolysis) to release oxygen, protons, and electrons. This reaction is essential for replenishing the electrons lost by PSII.

4. **Production of ATP and NADPH:**
The light energy captured by both photosystems is used to generate ATP through chemiosmosis and to reduce NADP+ to NADPH. This is a key difference from cyclic photophosphorylation, which only involves PSI and does not produce NADPH.

5. **Identifying the Correct Answer:**
The question asks which components perform non-cyclic photophosphorylation. Since both PSII and PSI are involved in this process, the correct answer is "both B and C."

**Final Answer:**
Non-cyclic photophosphorylation is performed by both Photosystem I (PSI) and Photosystem II (PSII). Therefore, the correct option is "both B and C."

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