Lesson #20 Classification of carbohydrates

Carbohydrates are clarified as

1. Monosaccharide
2. Oligosaccharide
3. Polysaccharide

Monosaccharide:

Monosaccharide are the simplest carbohydrates. They can not be hydrolyzed. They have general formula (C. H2O)n where n is 3 to 6 carbon atoms. So Monosaccharide contain 3 to 6 carbon atom. They are further classified as trioses, tetroses, pentoses, hexoses etc. This classification is based on the number of carbon atoms they contain. The two most fimilar monosaccharide are glucose and fructose. Both have molecular formula C6H12O6.

Simple sugar:

Glucose is a pentahydroxy aldehyde, whereas fructose is a pentahydroxy ketone. Thier open chain are as follows. They are called simple sugars.

Dexto-rotatory or dextrose sugars:

Some monosaccharide molecules can rotate the plane of plane polarized light to right (colockwise). They are called dexto-rotatory or dextrose sugars.

Example:

Glucose, monose, galactose, are dextrose sugars.

Properties:

Monosaccharides are white crystalline solid. They are soluble in water and have sweet taste. They can not be hydrolyzed. They are reducing in nature.