Number of amino acids in A chain and B chain of insulin is:: (A) 30, 21, (B) 28, 32, (C) 32, 28, (D) 21, 30
Answer is D. Ans: d (21 and 30) Ref: Vasudevan,4th ed, p. 108Insulin is a protein hormone with 2 polypeptide chains; the A chain with 21 amino acids and B chain with 30 amino acids.Insulin:T 1/2 of insulin is 5 minutes.Normal daily insulin secretion is 50 units.Tissues independant of insulin - RBC, brain, renal medullary cells, placenta.Amino acids stimulating insulin secretion - leucine and arginine.Pork insulin differs from human insulin by only one amino acid residue.