And what that usually means is if this residue is found inside the active side of the enzyme, the presence of this modified phosphoryl group, what it basically does is it forms new interactions with, let's say, the substrate molecule. And that can in turn change the activity, the rate at which the enzyme actually catalyzes that particular reaction. So number one is this process gives a net negative charge and that's precisely what allows these new electric interactions to actually take place between this residue and that target substrate molecule. And this leads us directly into reason number two. As a result of this modified negatively charged groove found on this residue, because of this negative charge, that essentially gives this modified residue a high potential to form hydrogen bonds. And so the negatively charged oxygen atoms of the phosphorylated side chain residue can form hydrogen bonds with other molecules, for instance, the target enzyme or the target substrate molecule.