What type of inhibitors permanently deactivate enzymes by binding to the active site?

Irreversible inhibitors permanently deactivate enzymes by forming covalent bonds or strong non-covalent interactions at the active site of the enzyme. This binding typically alters the enzyme's structure or function permanently, meaning that once the inhibitor is attached, the enzyme cannot be reactivated by simply removing the inhibitor.

In contrast, competitive inhibitors bind reversibly to the active site, competing with the substrate but allowing the enzyme to return to normal function when the inhibitor is removed. Noncompetitive inhibitors bind elsewhere on the enzyme, changing its shape and functional capacity without directly blocking the active site. Reversible inhibitors also do not form permanent bonds and can dissociate from the enzyme, allowing recovery of enzyme activity.

The distinct characteristic of irreversible inhibitors lies in their ability to create permanent modifications to the enzyme's active site, leading to a loss of enzymatic function that cannot be reversed.