PH

• all enzymes have an optimum pH value, which is the pH at which the enzyme is most active
• most human enzymes work best at pH 7 but pepsin works best at pH2 and is found in the stomach
• pH1 is alkaline and pH7 is acidic
• above and below the optimum pH value the H+ and OH- ions found in acids and alkalis can mess up the ionic bonds and hydrogen bonds that hold the enzymes tertiary structure in place.

  makes active site change shape so enzyme is denatured