BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The Sakaguchi reagent is used to test for a certain amino acid and proteins. The amino acid that is detected in this test is arginine. Since arginine has a guanidine group in its side chain, it gives a red color with -naphthol in the presence of an oxidizing agent like bromine solution.

Detailed explanation-2: -Positive sakaguchi test: Red color ( Arginine) Negative sakaguchi test: no red color ( glycine, albumin)

Detailed explanation-3: -The guanidino (–C group in arginine reacts with the Sakaguchi reagent to form a red-coloured complex.

Detailed explanation-4: -The Sakaguchi reaction is a colorimetric reaction for identification and quantitation of guanidino groups, involving reaction with naphthol and sodium hypochlorite, providing a qualitative test for arginine that is free or in protein (10). This reaction was used by Fogg to show that heterocysts contain arginine (11).

Detailed explanation-5: -The Sakaguchi test proved that biological sex can be determined from the difference of male and female concentration ranges of arginine, an amino acid found in sweat.