The Glycogen molecule in 3-D

The Glycogen molecule - rotatable in 3 dimensions

Glycogen is a polysaccharide composed of glucose units linked by alpha 1-4 glycosidic bonds, with occasional alpha 1-6 glycosidic bonds which provide branching points.
(Zoom in to view branching point/ return to original view)

Each glycogen molecule may contain 60,000 glucose units, and each branch is about 8-12 glucose units in length, so that these molecules are bushy and nearly spherical in shape. The many exposed ends can have more glucose units added to them (glycogenesis) or removed from them (glycogenolysis). It is thus ideally suited for use as a short-term energy storage compound for excess glucose, which can also be quickly released for use in respiration,

Glycogen - also known as animal starch - is found in the liver and muscles. It is effectively similar in structure to the amylopectin fraction of starch, which has longer branches (24-30 glucose units).

This simple model - specifically prepared for this website by the Sweet program - shows a small section of a glycogen molecule consisting of 40 glucose units. The 1-4 linked sections can be seen to coil into a helical shape, and the two 1-6 linkages form helical branches away from the main section.

This helical structure is stabilised by hydrogen bonds between -OH groups on subsequent glucose units. Show ... hide H bonds.
Label/ Unlabel atoms

Web references

Glycogen From Wikipedia, the free encyclopedia
Glycogen from a sports training point of view
Sweet - a program for constructing 3D models of saccharides from their sequences using standard nomenclature