Bichemical Tests for Molecules
The Biuret Test (Proteins)
- Add a few drops of sodium hydroxide to make the solution alkaline.
- Then add some copper sulphate solution.
- If protein is present it will turn from blue to purple.
The Benedicts test (Sugars)
Include all monasaccharides and some disaccharides.
- Add benedicts reagant (blue) to sample.
- Heat it (Do not let it boil)
- If test is positive, it will form a cloudy precipitate.
- The precipitate goes from green-yellow-brick red.
- The higher the concentration is the further the colour changes.
- Alternatively, the solution can be filtered and the precipitate weighed.
Non - Reducing Sugars-
This is carried out after completing the test for reducing sugars.
- Break down the sugar into monosaccharides by boiling with dilute hydrochloric acid.
- Then add…