Answer to Question #57611 in Biochemistry for Sanjukta Ghosh

Question

What does actually occur- ATP is hydrolysed and esterification between glucose and HPO4 ^2-(formed as a result of hydrolysis) take place to form Glucose-6-phosphate or Nucleophilic attack of O- of glucose on ATP leads to formation of ADP and Glucose-6-phosphate?

Answer 1

Actually, this is a one-step reaction in which terminal phosphorus of ATP is attacked by O- of glucose in the presence of Mg2+. The role of hexokinase in this case is to fix both glucose and ATP in favorable positions (the phosphorylating activity of this enzyme enhances greatly after the binding of sugar as a result of so-called “induced fit”).

Source: Lehninger Principles of Biochemistry, 4 ed.