Which one of the following enzymes contains Mo as the prosthetic group?

Options

A. Phosphatase
B. Dehydrogenase
C. Isomerase
D. Nitrate reductase

Answer

To solve the question "Which one of the following enzymes contains Mo as the prosthetic group?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Prosthetic Groups**:
- Prosthetic groups are non-amino acid components that are tightly and covalently bound to enzymes. They are essential for the biological activity of the enzyme.

**Hint**: Remember that prosthetic groups are not part of the amino acid sequence but are crucial for enzyme function.

2. **Identifying Molybdenum's Role**:
- Molybdenum (Mo) is a metal that can serve as a prosthetic group in certain enzymes. We need to identify which enzyme requires Mo.

**Hint**: Think about the specific enzymes that are known to utilize metal ions as cofactors.

3. **Reviewing the Given Options**:
- The options provided are:
- Phosphatase
- Dehydrogenase
- Isomerase
- Nitrate reductase

**Hint**: Recall the functions of these enzymes and whether they are known to require metal ions.

4. **Analyzing Each Option**:
- **Phosphatase**: Typically does not require molybdenum.
- **Dehydrogenase**: Usually involves NAD+/NADH or FAD/FADH2, not molybdenum.
- **Isomerase**: Generally does not require metal ions.
- **Nitrate Reductase**: This enzyme is known to contain molybdenum as a prosthetic group and is essential for the reduction of nitrate to nitrite in plants.

**Hint**: Focus on the specific functions of nitrate reductase in nitrogen metabolism.

5. **Conclusion**:
- Based on the analysis, the enzyme that contains molybdenum as a prosthetic group is **Nitrate Reductase**.

**Final Answer**: Nitrate reductase is the correct answer.