Insulin: The Pancreatic Hormone & Its Role

The correct answer is: Insulin

Insulin is a polypeptide hormone secreted by the pancreas. In the form of monomers or small aggregates, insulin leaves the beta cells by exocytosis through the Golgi apparatus; the secretory granules that store insulin appear to contain zinc in order to form insulin's complex, hexameric structure (2 atoms of zinc are found for every 6 molecules of insulin in these granules).