Now, in our discussion on irreversible suicide inhibitors, we discussed penicillin. And we said that penicillin is an antibiotic that affects a specific bacterial enzyme found in bacterial cells known as glycopeptide transpeptidase. And when we discussed this molecule, we said that inside the active site of glycopeptide transpeptidase is this catalytic residue, namely this serene molecule. And the serene amino acid basically plays the catalytic role of actually forming a Covalent, a temporary Covalent bond between the oxygen and this carbon. So in this reaction, in the first step, this molecule actually forms a bond between the oxygen and this carbon, kicking off this terminal amino acid to form the following temporary transient acid intermediate molecule. Now, at the end of the reaction, of course, this bond is actually broken, but we formed the bond to basically keep this group attached into the active side so that another substrate can move in and grab this group.