LEARNING OBJECTIVES
in this article the author has explained about what are oligosaccharides, classification of oligosaccharides, examples and structures of oligosaccharides.
When 2-10 monosaccharides are linked through glycosidic bonds, oligosaccharides are formed. Sucrose, maltose, and lactose are some oligosaccharides.
Oligosaccharides are made up of carbon, hydrogen, and oxygen like other carbohydrates.
Oligosaccharides may be disaccharides, trisaccharides, etc based on the number of units of monosaccharides present.
Among oligosaccharides, disaccharides are the most common. So we will explain some features of disaccharides here:
Disaccharides definition
Table of Contents
When two units of monosaccharides are linked through the glycosidic bond, the carbohydrate which is formed is called a disaccharide.
Physical properties of Disaccharides
- Disaccharides are sweet in taste.
- They are crystalline in nature.
- Soluble in water.
- Disaccharides may have simple, linear, branched, and ring structures.
- Disaccharides are of two types; reducing and non-reducing.
- All disaccharides are optically active
Classification of disaccharides
Disaccharides are further classified into two classes:
1. Reducing sugar
The disaccharides with a free aldehyde or keto group are called reducing sugars. They are good reducing agents.
For example, maltose, and lactose
2. Non-reducing sugar
The disaccharides whose aldehyde or keto group is not free are called non-reducing sugars.
For Example, sucrose, trehalose.
Examples of Disaccharides
1. Maltose
Maltose is a disaccharide made up of two α-D-glucose. Carbon 1 of the first α-D-glucose is linked to carbon 4 of the next glucose.
2. Lactose
Lactose is commonly known as ‘milk sugar”.
It is a common disaccharide of milk.
Lactose is made up of two units; glucose and galactose.
3. Sucrose
Sucrose is a non-reducing sugar. Sweetest in taste and found in sugar cane and sugar beet. Sucrose is the sweetest among all the disaccharides.
Sucrose is made of α-D-glucose and β-D-fructose.
4. Trehalose
Trehalose is almost similar to sucrose but not much common. It is made of two units of glucose. Many microorganisms like bacteria, fungi, etc synthesize trehalose as a source of energy. It is a non-reducing sugar.
This is a brief introduction of oligosaccharides. If you have any question regarding oligosaccharides let us know in the comment section.