Biology 5090 · O Level · Biological molecules

Biological molecules — practice question

Four food tests were performed separately on four white powders, A, B, C and D. The table shows the outcomes. Which powder contains a carbohydrate, a fat and a protein?

  • ABenedict’s test: blue colour; biuret test: violet colour; ethanol emulsion test: milky; iodine solution test: blue-black colour
  • BBenedict’s test: orange colour; biuret test: blue colour; ethanol emulsion test: milky; iodine solution test: blue-black colour
  • CBenedict’s test: red colour; biuret test: violet colour; ethanol emulsion test: clear; iodine solution test: yellow colour
  • DBenedict’s test: green colour; biuret test: blue colour; ethanol emulsion test: clear; iodine solution test: yellow colour

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