Question

Which one of the following is a disaccharide? \[ \text{Glucose, Lactose, Amylose, Fructose} \] 

Hint:

Disaccharides are made up of two monosaccharides joined by a glycosidic bond. Lactose is an example of a disaccharide.

Answer 1

Monosaccharides, Disaccharides, and Polysaccharides

A disaccharide is a carbohydrate formed by two monosaccharide units linked by a glycosidic bond. This section details the components within this classification.

Monosaccharides:

• Glucose, a monosaccharide and simple sugar, is a main energy source for the body.
• Fructose, another monosaccharide, is frequently found in fruits and honey.

Disaccharides:

• Lactose is a disaccharide comprising glucose and galactose monosaccharide units. It is a common sugar in milk, contributing to its sweetness.

Polysaccharides:

• Amylose is a polysaccharide composed of extensive glucose unit chains. It is a constituent of starch, the glucose storage form in plants.

Conclusion:

- Glucose and fructose are monosaccharides (single sugar units). - Lactose is a disaccharide, formed from glucose and galactose. - Amylose is a polysaccharide consisting of multiple glucose units.

Summary:

Therefore, from the presented examples, lactose is identified as the disaccharide, resulting from the glycosidic linkage between glucose and galactose.