How many polypepide chains does insulin compose of ?: (A) 4 chains, (B) 3 chains, (C) 2 chains, (D) 5 chains
Answer is C. Insulin is two-chain polypeptide hormone, with 51 amino acids. Structure: 2 chains - A & B chain. A - chain - 21 amino acids; B - chain - 30 amino acids. Half-life-: About 5 mins