glycogen

glycogen /gly·co·gen/ (gli´ko-jen) a highly branched polysaccharide of glucose chains, the chief carbohydrate storage material in animals, stored primarily in liver and muscle; it is synthesized and degraded for energy as demanded.glycogen´ic

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gly·co·gen (glk-jn)

n.

A polysaccharide that is the main form of carbohydrate storage in animals and occurs mainly in liver and muscle tissue; it is readily converted to glucose. Also called animal starch.

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glyco·genic (-jnk) adj.

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Glycogen

A macromolecule composed mainly of glucose that serves as the storage form of glucose that is not immediately needed by the body.

Mentioned in: Glycogen Storage Diseases

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glycogen

[glī′kəjən]

Etymology: Gk, glykys, sweet, genein, to produce

a polysaccharide that is the major carbohydrate stored in animal cells. It is formed from repeating units of glucose and stored chiefly in the liver and, to a lesser extent, in muscle cells. Glycogen is depolymerized to glucose, which is released into the circulation as needed by the body. Also called animal starch, hepatin, tissue dextrin. See also glucose.

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glycogen [gli´ko-jen]

a polysaccharide that is the chief carbohydrate storage material in animals, being converted to glucose by depolymerization; it is formed by and largely stored in the liver, and to a lesser extent in muscles, and is liberated as needed.

glycogen disease glycogen storage disease.

glycogen storage disease any of a group of genetically determined disorders of glycogen metabolism, marked by abnormal storage of glycogen in the body tissues. Type I is called gierke's disease; type II is called pompe's disease; type III is called forbes' disease; type IV is called amylopectinosis; type V is called mcardle disease; and type VI is called hers' disease. In type VII, a deficiency in phosphofructokinase affects muscle and erythrocytes, with temporary weakness and cramping of skeletal muscle after exercise. In type VIII, the enzyme deficiency is unknown, but the liver and brain are affected, with hepatomegaly, truncal ataxia, and nystagmus; the neurologic deterioration progresses to hypertonia, spasticity, and death. In type IX, a deficiency in liver phosphorylase kinase results in marked hepatomegaly, which may disappear in early adulthood. In type X, a lack of activity of cyclic AMP–dependent kinase affects the liver and muscle, with mild clinical symptoms. Called also glycogen disease and glycogenosis.

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glycogen (glī´kōjen),

n a branched, homopolysaccharide of glucose held by α 1-4 and α 1-6 glucosidic bonds. Liver glycogen provides a ready source of blood glucose through glycogenolysis.

glycogen storage disease,

n a group of inherited disorders of glycogen metabolism. An enzyme deficiency causes glycogen to accumulate in abnormally large amounts in various parts of the body. The full taxonomy runs from Type I to Type VII.

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glycogen

a polysaccharide, the chief carbohydrate storage material in animals. It is formed and stored in the liver and muscles (phosphorylytically cleaved to glucose-1-phosphate). Called also animal starch.

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glycogen granules

electron-dense accumulation of glycogen molecules.

glycogen nephrosis

deposition of glycogen in the renal tubules in diabetes mellitus but without apparent effect on renal function.

glycogen phosphorylase

glycogen phosphorylase the major enzyme in glycogenolysis, leading to the release of glucose-1-phosphate from glycogen. This enzyme is activated by phosphorylation from ATP by glycogen phosphorylase kinase, activated by cAMP-dependent protein kinase or by Ca²+ via calmodulin, or inhibited by hydrolysis of the phosphate by glycogen phosphorylase phosphatase.

glycogen synthase

an enzyme in the glycogenesis process.

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glycogen

Animal starch A polysaccharide of glucose-produced primarily in the liver and skeletal muscle, which is analogous to plant starch, but contains more highly branched chains of glucose subunits