BIOMOLECULES AND ENZYMES

Detailed explanation-1: -reagent is anthranol, the enol tautomer of anthrone, which reacts by condensing with the carbohydrate furfural derivative to give a green colour in dilute and a blue colour in concentrated solutions, which is determined colorimetrically. The blue-green solution shows absorption maximum at 620 nm.

Detailed explanation-2: -Bial’s test is useful in distinguishing pentoses sugar from hexoses sugars. Pentosses ( such as ribose sugar) form furfural in acidic medium which condense with orcinol in presence of ferric ion to give blue green colored complex which is soluble in butyl alcohol.

Detailed explanation-3: -Principle-Anthrone test is also another general test for all carbohydrates. In this test also, carbohydrate gets dehydrated when react with conc. H2SO4 to form furfural. This furfural reacts with anthrone to give bluish green colored complex.

Detailed explanation-4: -Result and Interpretation of Anthrone Test The presence of a blue-green complex indicates the presence of carbohydrates in the given solution.

Detailed explanation-5: -In this test, concentrated sulfuric acid converts the given carbohydrate into furfural or its derivatives, which react with -naphthol to form a purple coloured product. The chemical reaction is given below. Note: The appearance of purple or violet ring confirms the presence of carbohydrate.