Zn is a cofactor for

Options

A. Carboxy peptidase
B. Catalase
C. Peroxidase
D. Rubisco

Answer

To determine which enzyme zinc acts as a cofactor for, we need to analyze the options provided. The options are carboxypeptidase, catalase, peroxidase, and rubisco.

### Step-by-Step Solution:

1. **Understanding Cofactors**:
- Cofactors are non-protein chemical compounds that are required for the biological activity of some proteins, often enzymes. They can be organic (coenzymes) or inorganic (metal ions).

2. **Identifying the Enzymes**:
- **Carboxypeptidase**: This enzyme is involved in protein digestion, specifically in removing amino acids from the carboxyl end of proteins.
- **Catalase**: This enzyme catalyzes the decomposition of hydrogen peroxide into water and oxygen.
- **Peroxidase**: This enzyme catalyzes the oxidation of various substrates using hydrogen peroxide.
- **Rubisco**: This enzyme is involved in the first major step of carbon fixation in photosynthesis.

3. **Determining the Cofactor**:
- Among the options, carboxypeptidase is known to require zinc as a cofactor. Zinc plays a crucial role in the structural stability and catalytic activity of this enzyme.
- Catalase and peroxidase primarily use heme as a cofactor, while rubisco does not require zinc.

4. **Conclusion**:
- Based on the information, zinc is a cofactor for **carboxypeptidase**.

### Final Answer:
Zinc is a cofactor for **carboxypeptidase**.

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