Glycogen is the principal storage form of glucose in animal
cells. In humans and other vertebrates, most glycogen is found
in the skeletal muscles, but it is found in the highest
concentration in the liver (10% of the liver mass), giving it a
distinctive, "starchy" taste. In the Muscles glycogen is found
in a much lower concentration (1% of the muscle mass). In
addition, small amounts of glycogen are found in the kidneys,
and even smaller amounts in certain glial cells in the brain and
white blood cells. Structure and biochemistry Glycogen is a
glucose polymer resembling the starch in plants (so it is
sometimes called "animal starch"). Glycogen is a highly branched
glucose polymer. It is formed of small chains of 8 to 12 glucose
molecules linked together with α (1→4) bonds. These small chains
are in turn linked together with α (1→6) bonds. A single
molecule of glycogen can be made of up to 120,000 molecules of
glucose. It is stored in the form of granules in the cytosol.
These granules contain both glycogen a