NEET BIOLOGY

Detailed explanation-1: -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-2: -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.

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: -Testing for Proteins We used Biuret’s reagent to detect the presence of proteins in solution. The reagent is pale blue when pure, but when mixed with proteins, the resulting reaction produces a pale purple color. Left to right: Biuret’s reagent (BrR), water + BrR, egg albumin solution, egg albumin solution+ BrR.