Testing For Biological Molecules: Protein and Lipids

Question 1

How do we test for proteins?

Answer 1

= grind down food solution, filter solid food particles
= pour 2cm^3 into a test tube
= equal volume of sodium hydroxide at room temperature
= add few drop of diliute copper sulphate
= mix- lilac color means protein
= none- blue

Question 2

How do we test for lipids?

Answer 2

= Grind down food solution with distlled water
= 3cm^3 into a test tube
= 3cm^3 of ethanol and distilled water
= KEEP AWAY FROM NAKED FLAME
= gently shake (thumb on top)
= white emulision- lipids present
= colourless- lipids are not presrnt