BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Xanthoproteic Test is used to distinguish amino acids with a phenyl ring, a phenol or an indole group from other amino acids. This reaction is due to the nitration of phenyl rings present in Tyrosine, Phenylaline and trytophan (amino acids) to give Xanthoprotein yellow substituted products.

Detailed explanation-2: -Xanthoproteic test On the treatment of nitric acid, proteins give yellow precipitate which turns to orange color on treatment with alkali. Note: The appearance of a yellow color solution confirms the presence of proteins.

Detailed explanation-3: -If the test is positive the proof is neutralized with an alkali, turning dark yellow. The yellow colour is due to xanthoproteic acid which is formed due to nitration of certain amino acids, most common examples being tyrosine and tryptophan.

Detailed explanation-4: -The Xanthoproteic test uses a nitration reaction to determine the presence of proteins in a solution. When the sample is treated with a hot, concentrated nitric acid it reacts with aromatic amino acids such as phenylalanine, tyrosine and tryptophan and forms a yellow colored product known as Xantho protein.