Biology 5090 · O Level · Biological molecules

Biological molecules — practice question

A learner examined a food sample, and the findings were as follows. Colour after adding Benedict’s solution and heating: red. Colour after adding biuret reagent: purple. Colour after adding iodine solution: yellow/brown. Which nutrients were present in the food?

  • Aprotein, starch and reducing sugar
  • Bprotein and starch only
  • Cprotein and reducing sugar only
  • Dstarch and reducing sugar only

Worked solution & mark scheme

This 1-mark question has a full step-by-step worked solution and mark scheme.

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI