Carbohydrates or saccharides are biomolecules consisting of carbon (C), hydrogen (H), and oxygen (O).
Some examples of this kind of biomolecule are sugars, starch, and cellulose.
Carbohydrates can be classified by the number of units of saccharides that form the molecule, the more units, the more complex is the molecule.
Monosaccharides have only one unit; disaccharides have two units; oligosaccharides have a few numbers of units, usually between three and ten; and finally, polysaccharides are the more complex of the carbohydrates, having more than ten units.