ABSTRACT
Carbohydrates, as the name suggests, are molecules mainly made up of carbon, oxygen and hydrogen atoms. They are abundant in nature, constituting a significant portion of our diet, and serve mainly as energy stores, e.g., starch in plants and glycogen in animals. Carbohydrates also act as structural materials, like cellulose in plants, peptidoglycans in bacteria and chitin in the exoskeletons of arthropods. Derived from the Latin word saccharum for sugar, which itself has its origin in the Sanskrit word sarkhara, carbohydrates are commonly classified as monosaccharides, disaccharides, trisaccharides, oligosaccharides and polysaccharides. Monosaccharides are generally represented by the empirical formula CnH2nOn or Cn.(H2O)n. The latter representation led to the belief that they are hydrates of carbon, and so this family of compounds came to be called “carbohydrates.” Fischer projection formulae are widely used to denote the structure of carbohydrates and to identify unambiguously the configurations at the various chiral centers.
