Which is a powerful reducing agent utilised in the reduction of `CO_(2) to carbohydrates in the carbon reaction of photosynthesis?

Options

A. NADP
B. `NADPH^(+)`
C. NADP reductase
D. Ferredoxin

Answer

To answer the question regarding which powerful reducing agent is utilized in the reduction of CO2 to carbohydrates during the carbon reactions of photosynthesis, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Photosynthesis**: Photosynthesis consists of two main stages: the light-dependent reactions and the light-independent reactions (Calvin cycle). The light-dependent reactions capture energy from sunlight and produce ATP and NADPH.

2. **Identifying the Calvin Cycle**: The Calvin cycle is where CO2 is fixed and converted into carbohydrates. This cycle involves several steps, including carboxylation, reduction, and regeneration of ribulose bisphosphate (RuBP).

3. **Role of Reducing Agents**: In the Calvin cycle, reducing agents are crucial for the conversion of 3-phosphoglycerate (3-PGA) into glyceraldehyde-3-phosphate (G3P), which is a precursor for glucose and other carbohydrates.

4. **Key Reducing Agents**: The main reducing agent in the Calvin cycle is NADPH, which is produced during the light-dependent reactions. NADPH provides the necessary electrons for the reduction of 3-PGA to G3P.

5. **Conclusion**: Therefore, the powerful reducing agent utilized in the reduction of CO2 to carbohydrates in the Calvin cycle is **NADPH**.

### Final Answer:
The powerful reducing agent utilized in the reduction of CO2 to carbohydrates in the carbon reactions of photosynthesis is **NADPH**.

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