glycogen


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Related to glycogen: cellulose, glycogen storage disease, Glycogen phosphorylase

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.

gly·co·gen

(glī'kō-jen),
A glucosan of high molecular weight, resembling amylopectin in structure [with α(1,4) linkages] but with more highly branched α(1,6) linkages, as well as a small number of α(1,3) linkages; found in most tissues of the body, especially those of the liver and muscle; as the principal carbohydrate reserve, it is readily converted into glucose.

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

glycogen

(glī′kə-jən)
n.
A polysaccharide, (C6H10O5)n, that is the main form of carbohydrate storage in animals and is found primarily in the liver and muscle tissue. It is readily converted to glucose as needed by the body to satisfy its energy needs. Also called animal starch.

gly′co·gen′ic (-jĕn′ĭk) adj.

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.

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

gly·co·gen

(glī'kō-jen)
A glucosan of high molecular weight, resembling amylopectin in structure [with α(1,4) linkages] but with even more highly branched α(1,6) linkages, as well as a small number of α(1,3) linkages, found in most of the tissues of the body, especially those of the liver and muscle; as the principal carbohydrate reserve, it is readily converted into glucose.
Synonym(s): animal starch.

glycogen

A polysaccharide formed from many molecules of the monosaccharide glucose and found in the liver and in the muscles. It is the primary energy store of the body as it breaks down readily to release molecules of glucose. Glycogen has been called ‘animal starch’.
Glycogenclick for a larger image
Fig. 176 Glycogen . Formation and breakdown of glycogen in the liver.

glycogen

the principal carbohydrate storage molecule of animals, being produced from glucose in the mammalian liver (see PHOSPHATASE and muscles when blood sugar levels are too high, a process called glycogenesis which is under the influence of INSULIN. Glycogen in the liver can be broken down to glucose when blood sugar levels are low, a process called glycogenosis which is under the influence of GLUCAGON. See Fig. 176 . Glycogen in the muscle, however, is broken down to LACTIC ACID (not glucose) in GLYCOLYSIS.

Glycogen

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

glycogen

branched polysaccharide formed of glucose subunits. Glycogen accumulation in liver and skeletal muscle is the principal way of storing ingested carbohydrate. The liver normally contains ∼100 g (energy value 400 kcal) and skeletal muscle ∼400 g (1600 kcal) of glycogen. It is also stored in the brain. The body's upper limit for glycogen storage is ∼1050 g. It is known that aerobic endurance performance is directly related to the initial muscle glycogen and that perception of fatigue during prolonged exercise parallels the decline in these stores. See also carbohydrate, carbohydrate loading, glycogenesis.

glycogen

starch-like glucosan; readily converted into glucose; principal carbohydrate reserve, stored in skeletal muscle and liver

gly·co·gen

(glī'kō-jen)
A glucosan of high molecular weight, found in most of the tissues of the body, especially those of the liver and muscle; as principal carbohydrate reserve, readily converted into glucose.
Synonym(s): animal starch.

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.

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.

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.
References in periodicals archive ?
Correlation between levels of blood glucose and lactate and contents of muscle glycogen and lactate
Rates of glycogen recovery from the feedings also were not different between the diets.
Both hepatopancreas glycogen and muscle glycogen were significantly affected by dietary CBH levels, showing a pattern of up and down with an increase of dietary CBH.
Liver glycogen metabolism of control and experimental animals were shown in Table 5.
A diagnosis of glycogen storage disease type 1a was made with increased amount of glycogen and decreased G6Pase activity in the liver biopsy specimens and/or mutation analysis in the G6Pase gene.
So during an intense, prolonged activity, you can run out of glycogen.
IL-6 release from contracting muscle during exercise provides a signal to produce liver glucose, regulates the muscle substrates consumption, and enhance the glycogen sources and fat oxidation.
Much of the belief and research about glycogen comes from performance studies on distance runners, which clearly show that those who are glycogen loaded perform better.
The timing of post-exercise nutrition is an important factor to consider when attempting to replenish glycogen stores that may have been depleted from exercise.
Glycogen levels can be further augmented and returned to normal pre-match levels within the 36 hours that follow exhaustive exercise if players follow a proper dietary regimen, take the proper supplements (ergogenic aides) and receive adequate rest.
The Carbohydrate Energy Drink is a concentrated carbohydrate source for effective glycogen loading.
For example, participants following a low-calorie diet got about 40 percent of their glucose from glycogen, which comes from ingested carbohydrates and is stored in the liver until the body needs it.