Carbohydrates is the most widely distributed, naturally occurring organic compounds on Earth.
Carbohydrates are major nutrients which supply the body with energy and of which billions of tons are produced every year though photosynthesis by plants and cyanobacteria.
The term carbohydrate literally means ‘carbon + water’ and partially describe its chemical makeup.
It was found in the nineteenth century that carbohydrates in general have formula Cn(H2O)n. They were therefore thought to be hydrates of carbon and hence were called carbohydrates.
Later it was found that carbohydrates in fact contain hydroxyl groups and carbonyl groups and are polyhydroxy aldehydes or ketones.
Carbohydrate also called saccharides an are usually divided onto three groups: monosaccharides, disaccharides and polysaccharides. Saccharides was from Greek word ‘sakcharon’ meaning sugar.
The term ‘monosaccharide’ refers to a carbohydrate derivative possessing a single carbon chain: ‘disaccharide’ and ‘trisaccharide’ refer to molecules containing two or three such monosaccharides units joined together by acetal or ketal linkages.
Carbohydrates posses a large number of functionalities, at least one carbonyl and several hydroxyl per monosaccharide and often carry kinds of functional groups.
The meaning of carbohydrate
