Above the optimum temperature an enzyme's activity falls because

  1. the enzyme is killed
  2. there is too much kinetic energy for collisions
  3. the active site changes shape and the enzyme is denatured
  4. the substrate is denatured
Answer

C) the active site changes shape and the enzyme is denatured

Denaturation changes the active site shape. O Level Biology · Topic 5 Enzymes · 5.2 Effects of temperature and pH

Biology MCQ · More O Level Biology: Enzymes MCQs · Practise