Component of nitrogenase and nitrate reduction is

Options

A. Mo
B. Mn
C. Co
D. N

Answer

### Step-by-Step Solution:

1. **Understanding Nitrogenase and Nitrate Reduction**:
- Nitrogenase is an enzyme complex responsible for the conversion of atmospheric nitrogen (N₂) into ammonia (NH₃) during nitrogen fixation.
- Nitrate reduction refers to the process where nitrates (NO₃⁻) are converted into nitrites (NO₂⁻) and further into ammonia, which is essential for plant nutrition.

2. **Identifying Components of Nitrogenase**:
- Nitrogenase is composed of multiple components, including proteins and metal cofactors. One of the key metal cofactors is molybdenum.

3. **Role of Molybdenum**:
- Molybdenum is an essential trace element that is a part of the enzyme molybdoflavoprotein, which is crucial for the functioning of nitrogenase.
- It plays a significant role in the catalytic activity of nitrogen fixation.

4. **Nitrate Reductase**:
- Nitrate reductase is another enzyme involved in the reduction of nitrate to nitrite and is also dependent on molybdenum for its activity.
- Both nitrogenase and nitrate reductase require molybdenum as a cofactor for their enzymatic functions.

5. **Conclusion**:
- Therefore, the component common to both nitrogenase and nitrate reduction is **molybdenum**.

### Final Answer:
The component of nitrogenase and nitrate reduction is **molybdenum**.

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