<P> Monosaccharides can be linked together into what are called polysaccharides (or oligosaccharides) in a large variety of ways . Many carbohydrates contain one or more modified monosaccharide units that have had one or more groups replaced or removed . For example, deoxyribose, a component of DNA, is a modified version of ribose; chitin is composed of repeating units of N - acetyl glucosamine, a nitrogen - containing form of glucose . </P> <P> Carbohydrates are polyhydroxy aldehydes, ketones, alcohols, acids, their simple derivatives and their polymers having linkages of the acetal type . They may be classified according to their degree of polymerization, and may be divided initially into three principal groups, namely sugars, oligosaccharides and polysaccharides </P> <Table> The major dietary carbohydrates <Tr> <Th> Class (DP *) </Th> <Th> Subgroup </Th> <Th> Components </Th> </Tr> <Tr> <Th> Sugars (1--2) </Th> <Td> Monosaccharides </Td> <Td> Glucose, galactose, fructose, xylose </Td> </Tr> <Tr> <Td> Disaccharides </Td> <Td> Sucrose, lactose, maltose, trehalose </Td> </Tr> <Tr> <Td> Polyols </Td> <Td> Sorbitol, mannitol </Td> </Tr> <Tr> <Th> Oligosaccharides (3--9) </Th> <Td> Malto - oligosaccharides </Td> <Td> Maltodextrins </Td> </Tr> <Tr> <Td> Other oligosaccharides </Td> <Td> Raffinose, stachyose, fructo - oligosaccharides </Td> </Tr> <Tr> <Th> Polysaccharides (> 9) </Th> <Td> Starch </Td> <Td> Amylose, amylopectin, modified starches </Td> </Tr> <Tr> <Td> Non-starch polysaccharides </Td> <Td> Glycogen, Cellulose, Hemicellulose, Pectins, Hydrocolloids </Td> </Tr> </Table> <Tr> <Th> Class (DP *) </Th> <Th> Subgroup </Th> <Th> Components </Th> </Tr>

Select all that are types of carbohydrates found in living organisms