And protein kinase is basically phosphorylate while protein phosphatases defosphorylate. And they use the following hydrolysis reaction. So basically this is that modified residue of that enzyme. And what protein phosphatases do is they use a water molecule to basically remove this group and produce reform this enzyme that now contains this original residue that we basically had right over there. So these are the seven reasons for why phosphorylation is a very effective and a very convenient process. So again, it produces a residue that is modified and contains a net negative charge.