Question

Which of the following(s) is/are incorrect for lactose?

• A. It is a non-reducing sugar
• B. Glycosidic bond $[1,4]$ between glucose and galactose
• C. Glycosidic bond $[1,4]$ between glucose and fructose
• D. Glycosidic bond $[1,2]$ between glucose and galactose

Answer 1

Answer: (A), (C), (D)

Glycosidic bond $[1,2]$ between glucose and galactose

In lactose, there is a glycosidic bond $[1,4]$ between glucose and galactose where $C1$ of galactose is connected with $C4$ of glucose. It is a disaccharide and is found in milk. It is a reducing sugar because it has hemiacetal group.

Hence, (a), (c) and (d) are incorrect statements about lactose.