In what way do irreversible inhibitors differ from reversible inhibitors?

Irreversible inhibitors differ from reversible inhibitors primarily in their mechanism of action, specifically in how they interact with the enzyme. Irreversible inhibitors form permanent covalent bonds with the enzyme, leading to a long-lasting effect on the enzyme's activity. Once an irreversible inhibitor has bound to the active site or another important site on the enzyme, it effectively disables the enzyme permanently, which is why the inhibition is "irreversible."

In contrast, reversible inhibitors bind to enzymes through non-covalent interactions, such as hydrogen bonds or ionic interactions. This allows them to easily dissociate from the enzyme and restore its activity. Thus, the permanence of the bond formed by irreversible inhibitors is what distinguishes them from reversible inhibitors, thereby making the option that states they form permanent bonds with the enzyme the correct answer.

Other choices, such as those suggesting that irreversible inhibitors bind non-specifically or only inhibit competitive sites, do not accurately describe the key differences in their mechanism of action compared to reversible inhibitors.