The proteinaceous molecule that joins a non-protein prosthetic group to form a functional enzyme, is called

Options

A. apoenzyme
B. co-factor
C. holoenzyme
D. isoenzyme.

Answer

To answer the question, "The proteinaceous molecule that joins a non-protein prosthetic group to form a functional enzyme is called," we can break down the concepts involved:

### Step-by-Step Solution:

1. **Understanding Enzymes**: Enzymes are biological catalysts that speed up chemical reactions in the body. They are primarily proteins made up of long chains of amino acids.

2. **Defining Holoenzyme**: The functional form of an enzyme is referred to as a holoenzyme. A holoenzyme consists of two main components: the apoenzyme and the cofactor.

3. **Identifying Apoenzyme**: The apoenzyme is the protein part of the holoenzyme. It is the inactive form of the enzyme that requires a non-protein component to become active.

4. **Understanding Cofactors**: Cofactors can be either organic or inorganic. When the cofactor is an organic molecule that is tightly bound to the apoenzyme, it is specifically referred to as a prosthetic group.

5. **Prosthetic Group**: A prosthetic group is a non-protein component that is essential for the activity of the enzyme. It is tightly bound to the apoenzyme and cannot be easily removed.

6. **Conclusion**: Therefore, the proteinaceous molecule that joins a non-protein prosthetic group to form a functional enzyme is called the **apoenzyme**.

### Final Answer:
The proteinaceous molecule that joins a non-protein prosthetic group to form a functional enzyme is called **apoenzyme**.

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