Insulin of different organism differs in their structure. Human insulin consists of 51 amino acids with molecular weight of 58.08 KDa. It is composed of two chains α and β which are linked by disulphide bond to form insulin dimer. It is synthesised from beta cells of pancreas as a single polypeptide known as preinsulin which contains a 24 amino acid signal peptide responsible for directing it to rough endoplasmic reticulum where it is cleaved to form proinsulin. proinsulin is converted into mature insulin by the action of cellular endopeptidases and exoproteasecarboxypeptidase E.Glucagon is a 29 amino acid catabolic hormone. It is synthesised by alpha cells of pancreas by the cleavage of a 160 amino acid precursor known as preproglucagon. Similar to insulin, preglucagon is converted into proglucagon at rough endoplasmic reticulum (2). Proglucagone is then converted into mature glucagon by proteolytic cleavage. The secretion of glucagon is regulated by both blood glucose level and insulin. When, blood glucose level or insulin level increases, glucagon is secretion is inhibited. In addition, certain hormones such as catecholamines and cortisol stimulate the glucagon secretion.Both insulin and glucagon is degraded through different pathways after their action.