Biochemical Tests for molecules

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)

Reducing 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…