Ether links are very important in forming carbohydrates for use in animal systems and cellulose for the building of structural growth material for plants. Cellulose is the main constituent of the cell wall of plant cells.

Formation of a disaccharide(polymer) from glucose molecules(monomers) is pictured below. Longer polymers of sugar molecules found in the body include starch and glycogen. Glycogen is stored in the liver of animals. It provides a ready store of sugar when needed.

The reaction below forms the polymer and also a water molecule is released at every link formed. This polymerisation reaction is known as condensation polymerisation.