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 will follow these steps:

### Step 1: Understand the Question
We need to identify which enzyme from the given options contains molybdenum (Mo) as a prosthetic group. A prosthetic group is a non-polypeptide unit that is tightly and permanently attached to a protein and is essential for its activity.

### Step 2: Analyze the Options
The options provided are:
A. Phosphate
B. Dehydrogenase
C. Isobarase
D. Nitrate reductase

### Step 3: Recall Information about Enzymes and Cofactors
Enzymes can have different types of cofactors:
- **Prosthetic groups**: Tightly bound to the enzyme.
- **Coenzymes**: Loosely associated and can be removed.
- **Metal ions**: Can assist in enzyme activity but are not always tightly bound.

### Step 4: Identify the Role of Molybdenum
Molybdenum is known to be a component of certain enzymes, particularly those involved in redox reactions. One well-known enzyme that contains molybdenum is nitrate reductase, which catalyzes the reduction of nitrate to nitrite.

### Step 5: Match the Information
From our analysis, we recognize that:
- **Nitrate reductase** is an enzyme that contains molybdenum as a prosthetic group.

### Step 6: Conclusion
Based on the information gathered, the answer to the question is:
**D. Nitrate reductase**