In the amylase–starch investigation, the end point is reached when

  1. Benedict's turns brick-red
  2. bubbles stop forming
  3. iodine turns blue-black
  4. iodine no longer turns blue-black
Answer

D) iodine no longer turns blue-black

Starch has been broken down when iodine stays orange-brown. O Level Biology · Topic 5 Enzymes · 5.2 Effects of temperature and pH

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