BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The biuret reaction is based on the complex formation of cupric ions with proteins. In this reaction, copper sulfate is added to a protein solution in strong alkaline solution. A purplish-violet color is produced, resulting from complex formation between the cupric ions and the peptide bond.

Detailed explanation-2: -Therefore, the biuret test can also be used to gauge the amount of protein present in the analyte. In this test, the presence of peptides results in the formation of pale purple coloured (or mauve coloured) coordination compounds of the copper(II) ion (when the solution is sufficiently alkaline).

Detailed explanation-3: -Biuret Test Principle A Biuret test is a chemical test used to determine the presence of a peptide bond in a substance. It is based on the biuret reaction in which a peptide structure containing at least two peptide links produces a violet color when treated with alkaline copper sulfate.

Detailed explanation-4: -Proteins are made up of amino acid residues joined by peptide bonds. Due to the presence of peptide structure and the presence of different amino acid residues, proteins react with a variety of reagents to form colored products. These tests are known as color reaction of protein.

Detailed explanation-5: -Biuret solution consists of copper sulphate and sodium hydroxide. The food to be tested changes its colour to violet or purple indicating the presence of proteins.