BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Biuret solution is made by mixing copper sulfate with sodium hydroxide. Copper sulfate gives a typical blue color to this solution, which is turned to purple after reacting with the proteins. This test is called as ‘Biuret test’.

Detailed explanation-2: -As previously mentioned, if a sample is tested using the biuret reagent it will change to a purple color, if it contains protein.

Detailed explanation-3: -Purple foods contain anthocyanins, which are antioxidants that prevent and repair cellular damage. They are natural plant pigments that cause red and blue colors in certain plants.

Detailed explanation-4: -If a food gives purple or violet colour with the solution of copper sulphate and caustic soda, we can say that protein is present in it. The solution of copper sulphate and caustic soda is called ‘biuret solution’ and is blue in colour and it turns to violet or purple colour upon reacting with proteins.

Detailed explanation-5: -Biuret reagent is an alkaline solution of 1% CuSO4, copper sulfate. The violet color is a positive test for the presence of protein, and the intensity of the color is proportional to the number of peptide bonds in the solution.