Question

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 = Albumin
• B. A = Lactose B = Glucose C = Alanine
• C. A = Lactose B = Fructose C = Alanine
• D. A = Glucose B = Sucrose C = Albumin

Answer 1

The correct option is A

A = Lactose B = Glucose C = Albumin

1. Molisch's Test: Test that detects the presence of carbohydrates in the given sample.
2. Barfoed's Test: Test that detects the presence of monosaccharides in the given sample.
3. Biuret Test: Test that detects the presence of peptide bonds in in the given sample.
4. Lactose and glucose are carbohydrates, thus they give positive Molisch's test.
5. Glucose and fructose are monosaccharides, thus they give positive Barfoed's test.
6. Sucrose is a disaccharide, thus giving a negative biuret test.
7. Albumin is a protein and proteins contain peptide bonds, thus albumin gives a positive biuret test.
8. Alanine is an amino acid, thus giving a negative Biuret test.
9. So, $A,B,C$are lactose, glucose and albumin respectively.
10. Thus, the correct option is $\left(\mathit{A}\right)$.