Question

(a) The insulin synthesised in our body is different from that synthesised by Eli Lilly company using recombinant DNA technology. Differentiate between them.
(b) Why the insulin extracted from an animal source is not in use these days?

Hint:

Recombinant DNA technology allows production of human insulin in bacteria, avoiding the immunological issues associated with animal-derived insulin.

Answer 1

Step 1: For (a), human insulin produced in the body is a 51-amino-acid protein hormone made by pancreatic beta cells, while Eli Lilly’s insulin (e.g., Humulin) is synthesized using recombinant DNA technology in bacteria like E. coli, making it identical to human insulin but produced artificially. The difference lies in production: natural insulin is endogenous, while recombinant insulin is exogenous but structurally identical.
Step 2: For (b), insulin from animal sources (e.g., pigs or cows) is not widely used today because it differs slightly in amino acid sequence from human insulin, leading to potential immune reactions or allergies in some patients. Recombinant human insulin, being identical to human insulin, is safer and more effective.
Thus, recombinant insulin matches human insulin but is produced artificially, and animal insulin is avoided due to immunogenicity risks.