Well, the group specific inhibitor is an example of an Irreversible inhibitor that binds to and reacts with specific side chain groups of amino acids. For instance, on the board we have two examples of group specific inhibitors. We have Idoscenemide that reacts with Sistine side chains, and we also have di isopropyl phosphoridate, or simply DIPF that reacts with serine amino acids. For instance, if we take an enzyme that contains an active site, and inside that active site, we have a catalytic amino acid, namely the cysteine, well, then this Idocidamide will react with that catalytic amino acid, the cysteine, to form a covalent bond between this carbon here and this sulfur atom here. And because this is the sulfur atom, part of the side chain of the cysteine, that is used to basically catalyze some specific type of reaction, because we form a covalent bond, as shown in the following diagram, that essentially deactivates and inhibits the activity of that particular enzyme. And so, as a result of this covalent modification, we essentially deactivate that active side of the enzyme.