- glucose to glucose-6-phosphate
- fructose to fructose-6-phosphate
To do this, it requires the energy released by the conversion of one molecule of ATP to ADP.
Hexokinase is the first enzyme in the pathways of glycolysis, glycogenesis and the pentose phosphate pathway in non-hepatic tissue. In the liver, glucokinase carries out the same reaction.
As hexokinase is unsaturated, the route taken is dependent on the balance of activity of flux-generating enzymes of each pathway in a given cell.
Glucose-6-phosphate acts by negative feedback to inhibit hexokinase.
The formation of glucose-6-phosphate or fructose-6-phosphate also traps blood-derived glucose or fructose within the cell; they are incapable of transmembranous diffusion.
Last reviewed 01/2018