Read the following statements regarding the structure and production of human insulin: (a) Mature human insulin consists of two short polypeptide chains, chain A and chain B, that are linked together by hydrogen bonds. (b) In mammals, including humans, insulin is synthesised as a pro-hormone which contains an extra stretch called the C peptide. (c) An American company, Eli Lilly, prepared two DNA sequences correspond

Step-by-step solution

Statement (a) is incorrect because mature human insulin consists of two short polypeptide chains, chain A and chain B, that are linked together by disulphide bonds, not hydrogen bonds. Statement (b) is correct as insulin in mammals is synthesised as a pro-hormone containing an extra stretch called the C peptide, which is removed during maturation. Statement (c) is incorrect because Eli Lilly introduced the DNA sequences corresponding to A and B chains of human insulin into plasmids of E. coli , not Agrobacterium .