Glucokinase

Glucokinase is a hexokinase enzyme involved in the first step of glycolysis where glucose is transformed into glucose-6-phosphate (G6P). The energy required to phosphorylate glucose comes from one ATP. Glucokinase is found in the liver. In other parts of the body such as muscle or the brain, other hexokinase catalyzes the same reaction. Hexokinase is inhibited by G6P so when the energy demand of the tissue is satisfied, glucose stops being used. In contrast to this, glucokinase is not inhibited by G6P.