Question

Which reagents react with reducing sugars (but not non-reducing sugars), indicate each reagent that reacts (5 points): (i) Millon's reagent, (ii) Bradford’s reagent, (iii) Benedict’s reagent, (iv) Barfoed’s reagent, (v) Biuret reagent

Answer 1

B ) millons reagent   it is a Mixture of mercurous and mercuric nitrates. this reagent is mainly used to detect the amino acids (  Tyrosine ) but not the carbohydrates identification

Bradford Reagent  The Reagent can be used to determine the concentration of proteins in solution.but

not for the identification of carbohydrates

benedicts reagent   It is a complex mixture of sodium carbonate, sodium citrate and copper(II) sulfate pentahydrate. to detect the presence of reducing sugars. A positive test with Benedict's reagent is shown by a color change from clear blue to a brick-red precipitate.

barfoeds reagent it consist of a  0.33 molar solution of neutral copper acetate in 1% acetic acid solution.

it is majorily used to detect reducing sugars but not all simply monosaccharides .(Disaccharides may also react, but the reaction is much slower.) because some of the disaccharides also act as reducing sugars except sucrose .

biuret reagent   it is composed of potassium hydroxide and copper sulfate this test used for detecting the presence of peptide bonds ( proteins ) not used for the identification of carbohydrates