What gets removed during the processing of "proinsulin" to "insulin" ?

Options

A. A peptide is removed from proinsulin
B. C peptide is removed from proinsulin
C. A and B peptides are removed from proinsulin
D. B peptide is removed from proinsulin

Answer

To solve the question "What gets removed during the processing of 'proinsulin' to 'insulin'?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Proinsulin**:
- Proinsulin is a precursor molecule that is synthesized in the pancreas. It is a larger molecule that contains the necessary components to form insulin.

2. **Components of Proinsulin**:
- Proinsulin consists of three main parts: the A-chain, the B-chain, and the C-peptide. The A and B chains are the actual components of insulin, while the C-peptide is an additional segment.

3. **Processing of Proinsulin**:
- During the conversion of proinsulin to insulin, the proinsulin molecule undergoes enzymatic cleavage. This process involves the removal of the C-peptide.

4. **Formation of Insulin**:
- After the C-peptide is removed, the A-chain and B-chain are linked together by disulfide bonds to form the mature insulin molecule.

5. **Conclusion**:
- Therefore, the component that gets removed during the processing of proinsulin to insulin is the C-peptide.

### Final Answer:
The correct answer is: **C-peptide is removed from proinsulin**.

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