Holoenzyme is produced by

Options

A. Combined coenzyme and epoenzyme
B. Only prosthetic group
C. Only protein
D. Only cofactor.

Answer

### Step-by-Step Solution:

1. **Understanding Enzymes**: Enzymes are biological catalysts that speed up biochemical reactions. They are primarily proteins.

2. **Defining Apoenzyme**: The protein part of an enzyme that is inactive on its own is called the apoenzyme. It requires additional components to become active.

3. **Role of Cofactors**: Cofactors are non-protein molecules that assist enzymes in their catalytic activity. They can be either organic (coenzymes) or inorganic.

4. **Holoenzyme Definition**: A holoenzyme is the active form of an enzyme, which consists of the apoenzyme plus its cofactor (which can be a coenzyme or an inorganic ion).

5. **Analyzing the Options**:
- **Option 1**: Combined coenzyme and apoenzyme - This is correct because a holoenzyme is formed by the combination of an apoenzyme and a coenzyme.
- **Option 2**: Only proteostatic group - This is incorrect as it does not account for the cofactor.
- **Option 3**: Only protein - This is incorrect because it does not include the necessary cofactor.
- **Option 4**: Only cofactor - This is incorrect because it does not include the apoenzyme.

6. **Conclusion**: The correct answer is that a holoenzyme is produced by the combination of a coenzyme and an apoenzyme.

### Final Answer:
Holoenzyme is produced by the combination of coenzyme and apoenzyme.

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