Final answer:
An irreversible inhibitor is an inorganic substance that permanently inactivates an enzyme by forming a covalent bond at its active site. Cofactors like Fe²⁺ and Mg²⁺ are essential for the stability and function of some enzymes. Non-competitive inhibitors can also affect enzyme activity by binding elsewhere on the enzyme.
Step-by-step explanation:
An irreversible inhibitor is an inorganic substance that, when ingested, attaches to enzymes or other organic molecules in a manner that permanently inactivates the enzyme. This occurs by the inhibitor bonding covalently to a specific group at the active site of the enzyme. Unlike reversible inhibitors, irreversible inhibitors cause permanent changes to the enzyme, which prevent it from catalyzing its specific reaction.
Enzymes are natural catalysts that accelerate biological reactions within living organisms. Cofactors, which are inorganic ions like Fe²⁺ and Mg²⁺, can stabilize enzyme conformation and function. When an inorganic substance acts as a cofactor, it is essential for the optimal activity of the enzyme. An example is DNA polymerase, which requires a zinc ion (Zn²⁺) to function effectively.
Non-competitive inhibitors are another example of substances that can affect enzyme activity by binding to a site on the enzyme other than the active site. However, unlike irreversible inhibitors, their effect is not covalent and often reversible, allowing for the recovery of enzyme function when these inhibitors are no longer present.