LIFE SCIENCE

Detailed explanation-1: -Tyrosine when reacted with acidified mercuric sulphate solution gives yellow precipitate of mercury-amino acid complex. On addition of sodioum nitrate solution and heating, the yellow complex of mercury-amino acid complex converts to mercury phenolate which is in red color.

Detailed explanation-2: -Millon’s reagent is an analytical reagent used to detect the presence of soluble proteins. A few drops of the reagent are added to the test solution, which is then heated gently. A reddish-brown coloration or precipitate indicates the presence of tyrosine residue which occur in nearly all proteins.

Detailed explanation-3: -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-4: -A red solution or precipitate that forms in heating is an indication that tyrosine is present (a positive result). Since tyrosine is an amino acid occurring in nearly all proteins, Millon’s test is used for detecting proteins.

Detailed explanation-5: -Millon’s test is given by proteins containing phenolic amino acids. Gelatin does not give this test. First, a white precipitate is formed when proteins are treated with millions reagent and then turns to brick-red color on boiling, this confirms the presence of proteins.