Which is correct regarding genetically engineered insulin using E.coli ?

Options

A. Difficult to purify
B. Obtained in large unlimited quantities
C. Possibility of transmission of animal diseases
D. Insulin obtained varies in chemical structure.

Answer

### Step-by-Step Solution:

1. **Understanding the Context**:
- Insulin is a hormone produced by the beta cells of the pancreas and is crucial for regulating blood glucose levels. In patients with diabetes mellitus, insulin production is insufficient, necessitating external sources of insulin.

2. **Sources of Insulin**:
- Traditionally, insulin was derived from non-human sources like the pancreas of slaughtered cattle and pigs. However, this method can lead to allergic reactions in humans.

3. **Genetic Engineering of Insulin**:
- To overcome the limitations of animal-derived insulin, recombinant DNA technology is utilized. This involves isolating the genes responsible for producing the A and B chains of human insulin.

4. **Role of E. coli**:
- The genes for the A and B chains of insulin are introduced into the bacterium E. coli. This bacterium is capable of synthesizing these chains in large quantities.

5. **Production Process**:
- After the A and B chains are synthesized by E. coli, they are extracted and purified. The two chains are then combined through disulfide bridges to form the mature insulin molecule.

6. **Advantages of Genetically Engineered Insulin**:
- The insulin produced through this method is identical to human insulin, minimizing the risk of allergic reactions.
- It can be produced in large quantities, making it more accessible for patients.

7. **Evaluating the Options**:
- The question asks which statement is correct regarding genetically engineered insulin using E. coli. The correct option states that insulin can be produced in large quantities and is structurally identical to human insulin.

### Conclusion:
- The correct answer is that genetically engineered insulin using E. coli can be produced in large quantities and is structurally identical to human insulin.

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