Introduction Structure and Classification of Polysaccharides

Polysaccharides can be divided into two classes (1) homopolysaccharides consisting of only one kind of monosaccharide and (2) heteropolysaccharides consisting of two or more kinds of monosaccharide units. In the latter type, the arrangement or sequence of the monosaccharide units is usually in a definite, repeating pattern, rather than random. 

Essentials of Carbohydrate Chemistry Springer-Verlag New York Inc. 1998 

There are literally hundreds of different kinds of polysaccharides found in nature, especially when we consider microbial polysaccharides. It is therefore impossible to describe the structure and function of all of the known polysaccharides. We have focused on those that are best known and studied, those that have agricultural, biological, and commercial importance, those that have interesting properties and applications, and in some cases those that have an unusual structure. By doing this, we cover a broad range of polysaccharide structure, function, and application. 

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