Why do most enzymes stop functioning after being soaked in a strong acid or base?

Acids and bases determine pH. Acids have pH 0 - 7 while bases have pH 7 - 14. Enzymes function within a very narrow optimum range of pH. Different enzymes have different optimum pH values. This is the pH value at which the bonds within them are influenced by H + and OH - ions in such a way that the shape of their active site is most complementary to the shape of their substrate. Extreme changes in pH above or below the optimum as caused by strong bases and acids can cause the weak linkages e. g. hydrogen bonds in the enzyme's protein molecules to break permanently resulting in denaturation of the protein and impairing its functions because the enzyme can no longer conform its active site to complement that of its substrate and therefore no reaction can take place.