So the ultimate reason why we have these two different we have the aspartate and the spartic acid is because one transforms the water into a better nuclear file and the other one transforms the incoming substrate into a better electrophile. And now we can have our reaction take place. The similar reaction, the same type of reaction that took place here, we have this bond breaking, forming a bond with carbon, attacking the carbon nucleophilically, displacing the pi bond, forming that same type of tetrahedral intermediate. Except now, instead of having a bond between this residue and the carbon, we have a bond between the oxygen of the water and this carbon. So inside the active side of these proteins is a pair of aspartic acid residues. They work together to transform water into a good nuclear file so that it can hydrolyze that peptide bond.