And so they begin to pull away the H atom. And as the H atom is being pulled away, this is being transformed into nicoxide. And the coxide is a strong enough nucleopoly. It contains a high enough electron density around the oxygen as to actually attack nucleophilically this carbon of this peptide bond. And so once the carbon is attacked, that displaces the pi bond and places those two electrons that were initially in the pi bond onto this oxygen. So the serine alcohol acts as a nucleotide and attacks the carbon of the carbonyl.