For assimilation of one `CO_(2)` moleucles, the energy requried in form of ATP & `NADPH_(2)`

Options

A. `2 ATP & 2 NADPH_(2)`
B. `5 ATP & 3 NADPH_(2)`
C. `3 ATP & 2 NADPH_(2)`
D. `18 ATP & 12 NADPH_(2)`

Answer

To determine the energy required for the assimilation of one CO₂ molecule in terms of ATP and NADPH₂, we can break down the process step by step:

### Step-by-Step Solution:

1. **Understanding the Calvin Cycle**: The Calvin Cycle is the process by which plants fix carbon dioxide (CO₂) into organic molecules. It consists of three main phases: carbon fixation, reduction, and regeneration.

2. **Carbon Fixation**: In the first step, CO₂ is fixed by an enzyme called RuBisCO, which combines CO₂ with ribulose bisphosphate (RuBP) to form 3-phosphoglycerate (3-PGA).

3. **Reduction Phase**: The 3-PGA molecules are then converted into glyceraldehyde-3-phosphate (G3P) using energy from ATP and reducing power from NADPH₂. This is where the energy requirements come into play.

4. **Energy Requirements**: For the assimilation of one CO₂ molecule:
- **ATP Requirement**: It takes 3 ATP molecules to convert the fixed CO₂ into G3P.
- **NADPH₂ Requirement**: It takes 2 NADPH₂ molecules for the reduction of 3-PGA to G3P.

5. **Conclusion**: Therefore, the total energy required for the assimilation of one CO₂ molecule is:
- **3 ATP**
- **2 NADPH₂**

Thus, the answer to the question is that for the assimilation of one CO₂ molecule, **3 ATP and 2 NADPH₂** are required.

### Final Answer:
**3 ATP and 2 NADPH₂**