Holoenzyme is composed of :

Options

A. Non - protein and apoenzyme
B. protein and apoenzyme
C. Enyme , protein and coenzyme
D. Enzyme , non - protein and coenzyme

Answer

To solve the question "Holoenzyme is composed of:", we need to understand the components that make up a holoenzyme.

### Step-by-Step Solution:

1. **Definition of Holoenzyme**: A holoenzyme is a complete, active enzyme that consists of two main components: an apoenzyme and a cofactor. The apoenzyme is the protein part of the enzyme, while the cofactor can be a non-protein molecule that assists in enzyme activity.

2. **Understanding Apoenzyme**: The apoenzyme is the inactive form of the enzyme. It requires the cofactor to become active. The apoenzyme is typically a protein.

3. **Understanding Cofactor**: The cofactor can be either a metal ion (like zinc or magnesium) or an organic molecule (known as a coenzyme). The cofactor is essential for the enzyme's activity.

4. **Combining Components**: Therefore, a holoenzyme is formed when the apoenzyme (protein part) binds with its cofactor (non-protein part).

5. **Evaluating Options**:
- **Option 1**: Non-protein and apoenzyme - This is partially correct, as it mentions apoenzyme, but it does not specify the cofactor.
- **Option 2**: Protein and apoenzyme - This is incorrect because it does not mention the cofactor.
- **Option 3**: Enzyme, protein, and coenzyme - This is incorrect as it does not clearly define the components of a holoenzyme.
- **Option 4**: Enzyme, non-protein, and coenzyme - This is also incorrect as it does not specify the apoenzyme.

6. **Correct Answer**: The correct answer is **Option 1**: non-protein and apoenzyme, as it correctly identifies the components of a holoenzyme.