Which part of enzyme in a holoenzyme (conjugated enzyme) determines specificity of enzyme ?

Options

A. Aponezyme
B. Prosthetic group
C. Metal activator
D. None of these

Answer

To determine which part of the enzyme in a holoenzyme (conjugated enzyme) determines the specificity of the enzyme, we can break down the components of a holoenzyme and their functions.

### Step-by-Step Solution:

1. **Understanding Holoenzyme**:
- A holoenzyme is the complete, active form of an enzyme that consists of two main components: the protein part (apoenzyme) and the non-protein part (cofactor).

2. **Identifying Components**:
- The **apoenzyme** is the protein component of the enzyme.
- The **cofactor** can be either a prosthetic group (which is tightly bound to the enzyme) or a metal ion (which may be loosely associated).

3. **Role of Apoenzyme**:
- The specificity of an enzyme refers to its ability to select and catalyze a specific substrate. This specificity is primarily determined by the structure and properties of the apoenzyme.

4. **Conclusion**:
- Since the apoenzyme (the protein part) is responsible for the enzyme's specificity, we conclude that the part of the enzyme that determines specificity in a holoenzyme is the **apoenzyme**.

### Final Answer:
The part of the enzyme in a holoenzyme that determines specificity is the **apoenzyme**.

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