Diabetes mellitus by about two-thirds of the body's cells to absorb glucose from the blood for use as fuel, for conversion to other needed molecules, or for storage. Lower glucose levels result in decreased insulin release from the beta cells and in the breakdown of glycogen to glucose. This process is mainly controlled by the hormone glucagon, which acts in the opposite manner to insulin. If the amount of insulin available is insufficient, or if cells respond poorly to the effects of insulin (insulin insensitivity or insulin resistance), or if the insulin itself is defective, then glucose will not be absorbed properly
Glucose 6-phosphate body needs a way to store the excess glucose. After being converted to G6P, the molecule can be turned into glucose-1-phosphate by phosphoglucomutase. Glucose-1-phosphate can then be combined with uridine triphosphate (UTP) to form UDP-glucose, driven by the hydrolysis of UTP, releasing phosphate. Now, the activated UDP-glucose can add to a growing glycogen molecule with the help of glycogen synthase. This is a very efficient storage mechanism for glucose since it costs the body only 1 ATP to store the 1 glucose molecule and virtually no energy to remove it from storage. It is important to note that glucose-6-phosphate is