Prepare the sample you are testing, and add iodine solution. If starch is present in the sample, it will turn from a yellow-orange colour to a blue-black colour
1 of 5
Test for reducing sugars
When a reducing sugar is heated with alkaline copper sulphate (Benedict’s solution) the solution will change colour from blue to an orange-red. This is called Benedict’s test
2 of 5
Test for non-reducing sugars
If a substance does not react with Benedict’s solution.Boil the sample with hydrochloric acid. Cool the solution and neutralise it by adding sodium carbonate solution. Carry out the reducing sugar test again:
3 of 5
Test for lipids
Mix the sample with ethanol. Pour the mixture into water contained in another test tube. If there is lipid present, a cloudy white emulsion will form near the top of the water
4 of 5
Test for proteins
A protein test uses the biuret test. Biuret reagent is pale blue in colour, and is added to the sample. This results in a colour change to lilac.
5 of 5
Other cards in this set
Card 2
Front
Test for reducing sugars
Back
When a reducing sugar is heated with alkaline copper sulphate (Benedict’s solution) the solution will change colour from blue to an orange-red. This is called Benedict’s test
Comments
Report