Botany online 1996-2004. No further update, only historical document of botanical science!


Polysaccharides


Polysaccharides form a heterogeneous group of polymers of different length and composition. They are constructed from monosaccharide residues that are linked by glycosidic bonds. It has already been shown that

both alpha- and beta-glycosidic linkages exist.

These linkages may be located between the C1 (or C2) of one sugar residue and the C2, C3, C4, C5 or C6 of the second residue. A branched sugar results if more than two types of linkage are present in single molecule.

A polysaccharide may consist of one (homopolymer) or several types of monomers (heteropolymer).

These construction principles would allow an indefinite number of different polysaccharides. But only a fraction of these are actually found in nature, since only certain combinations won through in the course of evolution.

The most common sugar found in polysaccharides is glucose. Its polymers are called glucanes. In the following explanation about the construction principles of polysaccarides, only glucanes will be used as examples. Nevertheless, a huge amount of further homo- and heteropolymers exist especially in plants. Many of them are components of the cell walls. Some are widespread, others are refined to single plant groups.


© Peter v. Sengbusch - Impressum