Q.Insulin, a hormone chemically is

A hormone is an organic signalling substance -- a peptide or a steroid -- secreted by one tissue into the bloodstream to trigger a physiological response (e.g. growth, metabolic change) in a different tissue; it is, in short, an intercellular messenger. Hormones regulate nearly every body process: blood pressure/volume/electrolyte balance, embryogenesis, hunger, eating behaviour and digestion among them. They are produced by endocrine glands (pituitary, pineal, thymus, thyroid, adrenal glands, pancreas) and by the testes/ovaries. …