NEETChemistryBiomolecules
Considering the facts that I. sucrose forms glycosidic linkage between C₁ of glucose and C₂ fructose, while II. lactose forms glycosidic linkage between C ₁ of galactose and C ₄ of glucose. Choose the correct statement.
Options
- ABoth sucrose and lactose are reducing sugars.
- BBoth sucrose the lactose are non-reducing sugars.
- Clactose forms glycosidic linkage betwee C ₁ of galactose and C ₄ of glucose.
- DLactose is reducing sugar and sucrose is non-reducing sugar.
Correct answer
D. Lactose is reducing sugar and sucrose is non-reducing sugar.
Step-by-step solution
Sucrose and lactose both are disaccharides. In sucrose, anomeric- C₁ of -D-glucose and C₂ of -D-fructose are blocked by 1, 2-glycosidic linkage. So, it is a non-reducing sugar. In lactose, anomeric C ₁ of -D-galactose is blocked by 1,4-glycosidic linkage but anomeric- C ₁ of -D-glucose has free - OH group, which shows reducing property.