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  1. James N BeMiller

Published Online: 15 SEP 2009

DOI: 10.1002/9780470015902.a0000693.pub2



How to Cite

BeMiller, J. N. 2009. Polysaccharides. eLS. .

Author Information

  1. Purdue University, Indiana, USA

Publication History

  1. Published Online: 15 SEP 2009

This is not the most recent version of the article. View current version (16 JUN 2014)


Polysaccharides are carbohydrate polymers containing from approximately 35 (usually more than 100) to as many as 60 000 monosaccharide units. Polysaccharides have a range of general structures (from linear to various branched structures) and shapes. They are structural components of cell walls of bacteria, fungi, algae and higher plants and of the exoskeletons of insects and crustaceans, are energy- and carbon-storage substances, and serve various other functions as extracellular materials of plants, animals and microorganisms. They are the most abundant (by mass) of all organic substances in living organisms, comprising about two-thirds of the dry weight of the total biomass. Some have commercial value as isolated substances.

Key concepts

  • Polysaccharides are polymers of sugar (carbohydrate) units.

  • Polysaccharides are ubiquitous in nature. They are present in all plant tissues.

  • Polysaccharides comprise about three-fourths of the total biomass on Earth.

  • Polysaccharides serve as structural materials, as reserve food materials and in other functions.

  • Polysaccharides occur in a wide range of shapes and sizes.

  • Polysaccharides are hydrophilic and either dissolve in or absorb water.

  • Polysaccharides are produced and used commercially in large volumes.


  • polysaccharides;
  • glycans;
  • gums