With regard to insulin choose correct options. Choose the correct answer from the options given below.
- A and D only
- B and D only
- B and C only
- A, C and D only
Answer
(4) A, C and D only
Solution
As per NCERT, in mammals insulin is synthesised as a pro-hormone (pro-insulin) that contains an extra stretch called the C-peptide.
A: Correct – the C-peptide is removed during maturation, so it is not present in mature insulin.
B: Incorrect – in rDNA technology (Eli Lilly, 1983) the A and B chains were produced separately and combined; the product has no C-peptide.
C: Correct – pro-insulin has the C-peptide.
D: Correct – the two polypeptide chains A and B of insulin are linked together by disulphide bridges.
∴ Correct: A, C and D only.
Answer: (4)