Nitrate reductase enzyme:

Options

A. Reduces `NO_(2)^(-)`
B. oxidise `NO_(2)`
C. Reduces `NO_(3)^(-)`
D. oxidises `NO_(3)`

Answer

**Step-by-Step Text Solution:**

1. **Understanding Nitrate Reductase**: Nitrate reductase is an enzyme that plays a crucial role in the nitrogen cycle. It is responsible for catalyzing the reduction of nitrate (NO3) to nitrite (NO2).

2. **Identifying the Function**: The question asks about the specific function of the nitrate reductase enzyme. It is important to note that this enzyme primarily facilitates the reduction process.

3. **Reduction Process**: The reduction process involves converting a higher oxidation state to a lower one. In the case of nitrate reductase, it reduces nitrate (NO3) to nitrite (NO2).

4. **Analyzing the Options**: The options provided in the question are:
- Reduces NO2
- Oxidizes NO2
- Reduces NO3
- Oxidizes NO3

5. **Selecting the Correct Option**: Since nitrate reductase reduces nitrate (NO3) to nitrite (NO2), the correct answer to the question is that it reduces NO3.

6. **Conclusion**: Therefore, the correct answer to the question regarding the function of nitrate reductase enzyme is that it reduces NO3.

**Final Answer**: The nitrate reductase enzyme reduces NO3 (nitrate).

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