Insulin is a pancreatic hormone produced from the beta cell of islets of Langerhans of pancreas. It is a vital substance for utilization of glucose to convert into energy and stops body to produce energy from fat.
If body has enough insulin, that helps to store glucose as a glycogen in liver and muscle.
The level of sugar in our blood increases when we take food. The pancreas then release insulin to stabilize the excess sugar or glucose. In a healthy body, the body metabolism or the process of digestion and self growth is well balanced. A major part of the digested food is released into the blood stream as glucose. A constant supply of glucose is necessary to maintain the energy and growth of the cells in our body. However, our body cells cannot utilize the raw glucose. As glucose is being manufactured by the digestive process, at the same time our pancreas that produce insulin gets the signal to release sufficient amounts of insulin to facilitate the entry of glucose into the body cells. The cells need glucose to function normally, but glucose cannot enter the cells on its own; it has to wait for the presence of the hormone called insulin to penetrate the cells.