Find out a qualitative test for proteins, fats and oils, amino acids and test any fruit juice, saliva, sweat and urine for them. | NCERT solution | Class 11 Biology | Unit-9 Biomolecules



Q.12:- Find out a qualitative test for proteins, fats and oils, amino acids and test any fruit juice, saliva, sweat and urine for them.

 

Answer:

Qualitative tests for proteins, fats and oils are as follows:

Biuret Test: Biuret test is done for protein. Appearance of violet colour in the solution confirms the presence of protein. Biuret (H2NCONHCONH2) reacts with copper ion in a basic solution and gives the violet colour.



Liebermann-Burchard Test: This test is done for cholesterol. The reagent is a mixture of acetic anhydride and sulphuric acid. Appearance of green colour confirms the presence of cholesterol.

Grease Test: This test is done for certain oils. This is a simple test which involves rubbing the given sample on cloth or paper. Appearance of a translucent spot shows the presence of oil.