BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Millon’s test is specific to phenol containing structures (tyrosine is the only common phenolic amino acid). Millon’s reagent is concentrated HNO3, in which mercury is dissolved. As a result of the reaction a red precipitate or a red solution is considered as positive test.

Detailed explanation-2: -Millon’s Test Millon’s test is given by any compound containing a phenolic hydroxy group. Consequently, any protein containing tyrosine will give a positive test of a pink to dark-red colour.

Detailed explanation-3: -Millon’s Test: Proteins that contain tyrosine will, therefore, yield a positive result. However, some proteins containing tyrosine initially forms a white precipitate that turns red when heated, while others form a red solution immediately.

Detailed explanation-4: -All aryl amino acids give xanthoproteic test except phenylalanine, this is so because the benzene group present in phenylalanine is very stable and it does not react with nitric acid in normal conditions. Therefore, all amino acids do not give a positive xanthoproteic test.

Detailed explanation-5: -All proteins and peptides give positive results. Only amino acid, Histidine, gives a positive result.