Which is true statement ?

Options

A. `PEP`-pyruvate causes substrate level phosphorylation
B. PS `II` has oxygen producing complex
C. NADPH is assimilatory power
D. All the above.

Answer

To determine which statement is true regarding photosynthesis, we will analyze each statement provided in the question.

### Step-by-Step Solution:

1. **Understanding PEP and Substrate Level Phosphorylation**:
- PEP stands for phosphoenolpyruvate, which is a key intermediate in glycolysis.
- During glycolysis, PEP is converted to pyruvate, and this conversion involves substrate-level phosphorylation, leading to the formation of ATP.
- Therefore, the statement regarding PEP causing the formation of pyruvate through substrate-level phosphorylation is **true**.

2. **Analyzing PSII and Oxygen Production**:
- PSII refers to Photosystem II, which is involved in the light-dependent reactions of photosynthesis.
- PSII contains an oxygen-evolving complex that splits water molecules (H2O) into oxygen (O2), protons (H+), and electrons (e-).
- This process is crucial for replenishing the electrons lost by PSII during the light reactions.
- Hence, the statement about PSII being associated with the oxygen-producing complex is also **true**.

3. **Evaluating NADPH as Assimilatory Power**:
- NADPH is a crucial molecule produced during the light reactions of photosynthesis, specifically in the Z-scheme.
- It acts as an electron carrier and provides reducing power for the Calvin cycle, which is essential for the synthesis of glucose.
- Therefore, stating that NADPH is the assimilatory power is also **true**.

4. **Conclusion**:
- Since all the statements provided (about PEP, PSII, and NADPH) are true, we conclude that the correct answer is that all the statements are true.

### Final Answer:
All the statements provided in the question are true.

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