Biological molecules tests

• When testing for the biological molecule of starch, you use..

  • Iodine test - add a few drops to the sample in a spotting tile.
  • The colour of the chemical at the start is Orange-brown and a positive colour at the end is dark blue
• When testing for the biological molecule of Reducing sugars (carbohydrates), you use..

  • Benedict´s solution where you add equal volumes to the sample in a test tube and heat it in a water bath.
  • The colour at the start is blue and the positive colour at the end is a mix of colours, with them is green -yellow-orange-brick red.
• When testing for biological molecules of proteins , you use…

  • Biuret test where you add equal volumes to the sample in a test tube.
  • The colour of the chemical at the start is light blue and the positive colour at the end is violet
• When testing for the biological molecule of lips or fats , you use…

  • Emulsio test where you add equal volumes of ethanol and the sample into a test tube , you add a bung and shake it vigorously and pour the mixture into another test tube containing water.
  • The colour of the chemical at start is colourless ad the positive colour at the end is milk white