Well, first of all, it interacts with the active side of that enzyme. So it actually binds with residues on that active side. To be more specific, it binds with with 216 residues and one histidine residue. And once it binds it's able to actually interact with this substrate molecule. It polarizes this bond, weakens the bond and that's exactly what allows the Hydride to actually attack this carbon here and then allowing the H to go into this oxygen. And so ultimately we form ethanol and we regenerate that NAD plus.