Q. Consider the following statements about insulin I. Human insulin is made-up of 51 amino acids arranged in two polypeptide chains II. The two polypeptide chains are interconnected by two disulphide bridges III. In mammals including humans, insulin is synthesized as a pro-hormone, which contains an extra stretch called the C-peptide IV. C-peptide is not present in the mature insulin Which of the statements given above are correct?
A) I, II and III
B) I, III and IV
C) II, III and IV
D) I, II, III and IV
Explanation
Human insulin is made up of 51 amino acids arranged in two polypeptide chains. A having 21 amino acids and B with 30 amino acids. The two polypeptide chains are interconnected by two disulphide bridges or S-S linkages. S-S linkage also occurs in A-chain. The hormone develops from the storage product is called proinsulin. Proinsulin has three chains, A, B and C. C chain with 33 amino acids is removed prior to insulin formation
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.