Likewise, this bond will also not be cleaved because glycine is not a bulky hydrophobic or aromatic amino acid. So chimetrypsin is a serene protease that catalyzes the breaking the cleavage of peptide bond on the carboxyl side of bulky so, large hydrophobic or aromatic amino acids. Now, carmitrypsin is a serene protease and chimetrypsin is an example of an enzyme that utilizes the covalent catalysis mechanism. And what that means is inside the active side of kymatryptin, we have some type of nucleophilic residue that acts as the catalyst in forming a covalent bond, a temporary covalent bond between the active side of the enzyme and that peptide substrate molecule. Now, we say that the covalent bond is temporary because at the end of the reaction, that bond is broken. And that's important because we have to reform that unmodified enzyme, we have to regenerate that enzyme.