Enzymes can be structurally damaged, denatured, or rendered completely non-functional by three primary environmental factors: extreme heat, improper pH levels, and heavy metal toxicity. Excessively high temperatures disrupt the delicate hydrogen bonds and hydrophobic interactions holding an enzyme's precise three-dimensional tertiary structure together, causing it to unfold and lose its active site conformation. Similarly, exposing an enzyme to extreme acidic or basic pH environments alters the ionization states of its amino acid residues, while heavy metal ions bind irreversibly to functional groups, permanently inhibiting catalytic activity across biological and industrial systems.