During `N_(2)` fixation, reduction of one molecule of nitrogen into 2 molecules of `NH_(3)` consumes _____molecules of ATP.

Options

A. 4
B. 16
C. 56
D. 38

Explanation

To solve the question about the number of ATP molecules consumed during the nitrogen fixation process, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Process of Nitrogen Fixation**:
- Nitrogen fixation is the process by which nitrogen gas (N₂) is converted into ammonia (NH₃). This process is crucial for making nitrogen available to plants.

2. **Identify the Reaction**:
- The general reaction for nitrogen fixation can be represented as:
\[ N_2 + 8 \text{ electrons} + 8 \text{ protons} + 16 \text{ ATP} \rightarrow 2 \text{ NH}_3 + H_2 + 16 \text{ ADP} + 16 \text{ inorganic phosphate} \]

3. **Focus on the ATP Requirement**:
- From the reaction, it is clear that 16 molecules of ATP are required to convert one molecule of nitrogen (N₂) into two molecules of ammonia (NH₃).

4. **Conclusion**:
- Therefore, the answer to the question is that during nitrogen fixation, the reduction of one molecule of nitrogen into two molecules of NH₃ consumes **16 molecules of ATP**.

### Final Answer:
16 molecules of ATP.

---