Answer: irreversibly binds and inactivates the enzyme.
Explanation: An enzyme can be defined as any substance that binds substrates in a manner that facilitates the formation of product.
These are nonspecific factors that would inactivate any enzyme. The activity of enzymes can also be regulated by more specific inhibitors. A competitive inhibitor can be defined as an inhibitors bind reversibly at the active site of an enzyme.
It is important to note the difference:
An irreversible inhibitor inactivates an enzyme by bonding covalently to a particular group at the active site. The inhibitor-enzyme bond is so strong that the inhibition cannot be reversed by the addition of excess substrate.
A reversible inhibitor inactivates an enzyme through noncovalent, more easily reversed, interactions. Unlike an irreversible inhibitor, a reversible inhibitor can dissociate from the enzyme. Reversible inhibitors include competitive inhibitors and noncompetitive inhibitors.