Question

What products are obtained from the hydrolysis of lactose?

• A. Lactose + Glucose
• B. Glucose + Glucose
• C. Glucose + Fructose
• D. Galactose + Glucose

Hint:

Important disaccharides: Sucrose = Glucose + Fructose, Lactose = Glucose + Galactose, Maltose = Glucose + Glucose.

Answer 1

The Correct Option is D

Concept: Lactose is a disaccharide commonly known as milk sugar. It consists of two monosaccharide units joined through a glycosidic linkage. The constituent monosaccharides are: \[ \text{Glucose + Galactose} \] Upon hydrolysis, the glycosidic bond breaks and the constituent monosaccharides are obtained.

Step 1: Identify the composition of lactose. Lactose contains: \[ \text{Galactose} + \text{Glucose} \] joined by a \(\beta\)-glycosidic bond.

Step 2: Write the hydrolysis reaction. \[ \text{Lactose} + H_2O \longrightarrow \text{Glucose}+\text{Galactose} \] The water molecule breaks the glycosidic linkage.

Step 3: Match with the given options. The products formed are: \[ \boxed{\text{Galactose + Glucose}} \] Therefore, the correct option is \[ \boxed{(d)} \]