The compound sugars are made up of two or more molecules of monosaccharides and are further divided into two broad categories: oligosaccharides and polysaccharides.
Oligosaccharides and polysaccharides comprise two, several or many monomeric sugars covalently linked to each other by glycosidic bonds. Glycosidic bonds may have one of two orientations, termed alpha and beta.
Oligosaccharides, which are composed of two to nine, include sucrose (a disaccharide) and raffinose (a tri-saccharide).
The most common of the oligosaccharides is sucrose which contains two glycosidic-linked sugars, glucose and fructose. Some oligosaccharides serve storage functions a-in cells (e.g. sucrose, raffinose), whereas others accumulate as breakdown products from polysaccharides (e.g. maltose from starch, cellobiose from cellulose).
The polysaccharides are yield more than 1o molecules of monosaccharides on hydrolysis. They may be separated into three broad groups:
Homopolysaccharides (one kind of monosaccharide unit)
Heteropolysaccharides (two or more kinds of monosaccharides)
Nitrogen containing polysaccharides
Homopolysaccharides are composed of just one type of monosaccharide and heteropolysaccharides are built from more than one type. Typically, heteropolysaccharides molecule will be constructed from very few different monosaccharides.
The monosaccharides and disaccharides are sweet tasting and soluble in water. In contrast, the polysaccharides are colloidal, dispersible under certain conditions in water tasteless and vary greatly in digestibility.
Sugar compounds
