What is glucogen??
Glycogen is a polysaccharide which is composed by glucose. And it is using for keeping the energy in a short period in animal cell. And it is produced in the liver and muscle, but it also can be produce in brain and uterus. The reason that the glycogen called animal starch is in structure of its formation is allotrope of starch.

Structue of the glycogen is similar to amylopectin.And the glycogen is existed as a granule which can affect the metabolism circuit of the glucose.
And molecular formula of glycogen is →(C6H12O6)60000
How it affect??
And when the level of blood sugar is going down, glucagon cause the dissolution of the glycogen so the blood sugar level is going up. Because the glucagon makes the glycogen to glucose to raise up the blood sugar level. In the other hand when the level of blood sugar is going up the insulin is made by pancreas, so it makes the level of blood sugar go down.Because the insulin makes the glycose to glycogen.
diabetes-glucose-regulation.gif
And glycogen is not a hormone. It is block of clucose and the hormones such as insulin and glucagon are effective to control the bood sugar level.

Special point of glycogen
In muscle cell the glycogen works for supplying the glucose imediately. And the reason that the muscle contain the clycogen is in muscle there is no glucose-6-phosphatase which gives the ablility to blood to carry the sugar into muscle to give the energy, so the muscle contain the glycogen and it is wasted in mucles unlike the glycogen in liver.

What diseases are related with glycogen?
1.Hypoglicemia: The symtom which is caused by the low blood sugar level, because the secreting of rate of insulin is so high that disturbs the dissolving of glycogen, so it can not supply the glucose properly. The way of reducing this symtom is injecting glucagon which helps to dissolve the glycogen to glucose.
2.Diabetes: The symtom which is cause by the high blood sugar level, because the secreting of rate of insulin is so low that helps the dissolving of glycogen, so it supplys the clucose a lot into blood than normal situation. It causes lots of side effects. The way if reducing this symtom is injecting insulin which disturbs the dissolving of glycogen to glucose.


Refrences

The information about glycogen is from (http://ko.wikipedia.org/wiki/%EA%B8%80%EB%A6%AC%EC%BD%94%EA%B2%90)
which is from book Mc-Graw-Hill which is written by Saladin- Kenneth in 2007.

And the information about related diseases is from ( http://search.naver.com/search.naver?where=health_detail&sm=tab_txc&ie=utf8&query=%EB%8B%B9%EB%87%A8%EB%B3%91) which is written by Seoul national univerciy of KOREA in 2008 NOV 03th