Which statement about the effect of pH on enzyme-controlled reactions is not correct?
All human enzymes have an optimum pH of approximately 7.4.
Extreme pH values can break ionic and hydrogen bonds, disrupting the tertiary structure of the enzyme.
Changes in pH can alter the ionization (charge) of amino acid R-groups in the active site.
Small deviations from the optimum pH can reduce the reaction rate without causing permanent denaturation.
9 exam-style questions on OCR A A Level Biology Enzymes. Each one has a worked solution and a mark scheme showing where the marks go.