Number of disulphide linkages present in Insulin are _________.

Explanation

To determine the number of disulfide linkages present in insulin, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Insulin**:
- Insulin consists of two peptide chains known as Chain A and Chain B.
- Chain A contains 21 amino acid residues, while Chain B contains 30 amino acid residues.

2. **Identify Disulfide Linkages**:
- Disulfide linkages (or bridges) are formed between the sulfur atoms of cysteine residues in the peptide chains.
- In the structure of insulin, we need to look for the connections between Chain A and Chain B.

3. **Count the Disulfide Bridges**:
- Upon examining the structure of insulin, we find that there are two disulfide bridges that connect Chain A and Chain B.
- These linkages are crucial for the stability and functionality of the insulin molecule.

4. **Conclusion**:
- Therefore, the total number of disulfide linkages present in insulin is **2**.

### Final Answer:
The number of disulfide linkages present in insulin is **2**.

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