Chemistry
The Dynamic Equilibrium in Enzyme–Substrate Complexes at Different pH Values
Quick fact
Enzymes often lose activity at pH values outside their optimum because the pH affects the ionization state of amino acid side chains in the active site, altering the enzyme–substrate complex's ability to form or break down. For example, pepsin works best at pH 2, while trypsin works best at pH 8, even though both are proteases.
Why this is interesting
You may have noticed that when you take a drug or eat certain foods, the pH of your stomach or blood can change how well an enzyme works. But why do enzymes only work best at a specific pH, not all pH values?