composed of between two and ten polymerized monosaccharide units. Most oligosaccharides contain two (disaccharides), three (trisaccharides) or four (tetrasaccharides) sugar units. The most important plant sugar, *sucrose
, is a disaccharide. *Cellobiose
is another common disaccharide, being the basic repeating unit of cellulose. Other disaccharides include trehalose and gentiobiose. The commonest trisaccharide is *raffinose
and the commonest tetrasaccharide *stachyose
Oligosaccharides may be intermediates in polysaccharide metabolism or may serve as storage compounds.