So remember that the underlining, the defining point about Irreversible inhibitors is that they bind very strongly and so they will not let go of that enzyme very easily. That is what defines Irreversible inhibition. And once they bind, they change the confirmation. And so they essentially inhibit or block the activity of that enzyme. Now, there are many different examples of Irreversible inhibitors and three examples are listed on the board. So we have nerve gas, we have penicillin, and we have aspirin.