Well, whenever we have an ATP molecule and we have a water molecule in close proximity, remember the ATP is not very stable. And so the water molecule will generally want to hydrolyze and break down that ATP into ADP. And so by creating this environment in which we don't have any water molecules, what that does is it prevents any unwanted reactions, that is, it prevents the water from hydrolyzing the ATP into ADP. And what that means is the ATP can go ahead and transfer the enzyme can go ahead and transfer that phosphoryl group from the ATP onto this glucose molecule into producing that ADP. So the movement of the glucose into the active side of hexokinase causes the two domains, these two domains to basically rotate about twelve degrees. So they actually move about ten angstroms and that rotates these sections and closes that glucose molecule inside this active site, creating an induced fist and this seals off the glucose.