Non-protein part of holoenzyme is

Options

A. Vitamin
B. Cofactor
C. Fatty acid
D. Zymogen.

Answer

To answer the question regarding the non-protein part of a holoenzyme, we can follow these steps:

### Step-by-Step Solution:

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

2. **Structure of Enzymes**: Enzymes consist of two main components:
- **Apoenzyme**: This is the protein part of the enzyme and is inactive when alone.
- **Cofactor**: This is the non-protein part that is necessary for the enzyme's activity.

3. **Role of Cofactor**: The cofactor can be either:
- An organic compound (often referred to as a coenzyme, such as vitamins).
- An inorganic factor (such as metal ions).

4. **Formation of Holoenzyme**: When the apoenzyme (protein part) combines with the cofactor (non-protein part), they form a complete and active enzyme known as the holoenzyme.

5. **Identifying the Non-Protein Part**: The question specifically asks for the non-protein part of the holoenzyme. Based on our understanding:
- The non-protein part is referred to as the **cofactor**.

6. **Conclusion**: Therefore, the correct answer to the question "Non-protein part of holoenzyme is" is **cofactor**.

### Final Answer:
The non-protein part of a holoenzyme is called a **cofactor**.

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