Biochemistry, J.berg, J.Tymoczko, L.Stryer(2006)
When glucose enters cells, it is phosphorylated by ATP to form glucose 6-phosphate. This is an important step as glucose 6-phosphate cannot pass through the membrane as its not the substrate for glucose transporter. Also, the addition of the phosphoryl group acts to destablilze glucose, allowing it for further metabolism. While the transer of the phosphoryl group from ATPto glucose 6-phosphate is catayzed by hexokinase.