How many electrons and ATP are required for synthesis of 4 molecules of ammonia in `N_(2)` fixation metabolism?

Options

A. 8 and 16 respectively
B. 32 and 16 respectively
C. 16 and 32 respectively
D. 4 and 8 respectively

Answer

To determine how many electrons and ATP are required for the synthesis of 4 molecules of ammonia (NH₃) in nitrogen fixation metabolism, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Basic Reaction**:
The biological nitrogen fixation process converts atmospheric nitrogen (N₂) into ammonia (NH₃). The general reaction for the formation of ammonia from nitrogen can be represented as:
\[ N_2 + 8e^- + 8H^+ + 16 ATP \rightarrow 2NH_3 + H_2 + 16 ADP + 6Pi \]
This equation indicates that for every 2 molecules of ammonia produced, 8 electrons and 16 ATP are required.

2. **Calculate for 2 Molecules of Ammonia**:
From the equation, we see that to produce 2 molecules of ammonia, we need:
- 8 electrons
- 16 ATP

3. **Scale Up for 4 Molecules of Ammonia**:
Since the question asks for the synthesis of 4 molecules of ammonia, we need to double the amounts required for 2 molecules:
- Electrons required for 4 NH₃ = \( 8 \text{ electrons} \times 2 = 16 \text{ electrons} \)
- ATP required for 4 NH₃ = \( 16 \text{ ATP} \times 2 = 32 \text{ ATP} \)

4. **Final Answer**:
Therefore, for the synthesis of 4 molecules of ammonia, we require:
- **16 electrons**
- **32 ATP**

### Summary:
- **Electrons Required**: 16
- **ATP Required**: 32