Glucose is a crystalline, simple monosaccharide sugar that serves as the primary fuel for energy production in the human body. It is stored in the liver and muscles in its polymerized form called Glycogen. Its structural benefits include the production of glycoproteins, which function in the structure, reproduction, immune system, hormones, and protection of cells. While the human body carefully regulates glucose levels, irregularly high or low levels can result in serious illness. The brain requires a constant supply of sugar and when a body becomes hypoglycemic (abnormally low in blood glucose) its functions can begin to fail.