Glucose is a hexose sugar vital as a substrate for energy metabolism. For some tissues e.g. the brain, it is an obligatory energy source.
It is rarely found in its monosaccharide form e.g. in some fruit, but instead is abundant in the disaccharides maltose, lactose and sucrose, and in the polysaccharide starch.
Within the body glucose is stored as glycogen; occasionally, other compounds may be modified to create glucose e.g. in starvation.
Glucose is under the regulation of a homeostatic control system which aims to keep the fasting plasma concentration within narrow limits. Insulin-dependent diabetics are prone to fluctuations out of range: hyperglycaemia and hypoglycaemia following treatment.
Last reviewed 01/2018