A, B and C are three biomolecules. The results of the tests performed on them are given below: | | Molisch's Test | Barfoed Test | Biuret Test | |---|---|---|---| | (A) | Positive | Negative | Negative | | (B) | Positive | Positive | Negative | | (C) | Negative | Negative | Positive | A, B and C are respectively:

(B) A = Lactose, $\mathrm{B}=$ Glucose, $\mathrm{C}=$ Albumin

(A) $\mathrm{A}=$ Lactose, $\mathrm{B}=$ Glucose, $\mathrm{C}=$ Alanine

(C) $\mathrm{A}=$ Glucose, $\mathrm{B}=$ Fructose, $\mathrm{C}=$ Albumin

(D) $\mathrm{A}=$ Lactose, $\mathrm{B}=$ Fructose, $\mathrm{C}=$ Alanine

JEE Main · 2020 · 09 Jan 2020 · Shift 2 · Biomolecules

A, B and C are three biomolecules. The results of the tests performed on them are given below:

	Molisch's Test	Barfoed Test	Biuret Test
(A)	Positive	Negative	Negative
(B)	Positive	Positive	Negative
(C)	Negative	Negative	Positive

A, B and C are respectively:

(A) $A =$ Lactose, $B =$ Glucose, $C =$ Alanine
(B)A = Lactose, $B =$ Glucose, $C =$ Albumin✓ Correct
(C) $A =$ Glucose, $B =$ Fructose, $C =$ Albumin
(D) $A =$ Lactose, $B =$ Fructose, $C =$ Alanine

Answer: (B)

Solution

Molisch's test is a general test that all carbohydrates answer, so A and B are sugars while C, which fails it, is not a carbohydrate. Barfoed's test is answered only by monosaccharides, so B (positive) is a monosaccharide and A (negative) a disaccharide. The Biuret test is answered by proteins, so C, positive there, is a protein. These assignments make A the disaccharide lactose, B the monosaccharide glucose, and C the protein albumin.

JEE Main · 2020 · 09 Jan 2020 · Shift 2 · Single correct option

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JEE Main · 2020 · 09 Jan 2020 · Shift 2 · Biomolecules

Solution

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