These beta cells secrete the hormone insulin. Insulin basically acts as stage director when it comes to our energy metabolism. It's essential to our body's ability to utilize food. In the muscle cells that take in the glucose, it's converted to yet another chemical form called glycogen. The muscles then store the glycogen for use as an energy source.
Fat cells take in the fat.
Throughout these processes, insulin plays the role of director. Insulin tells the fat cells to take in the fat and store it, and the muscle cells to take in the sugar. Without insulin, or without enough of it, the body gets into serious trouble. The sugar in the bloodstream can't get transported into our muscle cells. So even though that blood sugar is available, it has nowhere to go, says Lawrence Hunsicker, M.D., professor of internal medicine at the University of Iowa College of Medicine in Iowa City.