Describe the chemical structure of insulin .

Explanation

Human insulin is synthesized by the `beta` cells of Islets of Langerhans in the pancreas. It is formed of 51 aminoacids which are arranged in two polypeptide chains, A and B . The polypeptide chain A has 21 amino acids while the polypeptide chain B has 30 amino acids. Both A and B chains are attacked together by disulphide bonds.