glycogen

Term: glycogen

Literally meaning: “producing sweet”

Origin: Greek

γλυκαγόνο/glycagοno(=glycogen)

>γλυκός/glycos(=sweet) as glycose, an older term for glucose +γεννώ/geno (=birth to, produce) >γένεσις/genesis(=origin) >γενεά/ genea(=generation

Coined/History

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Glycogen is the storage form of carbohydrate for virtually every organism from yeast to primates and for mammalian tissues the major depots located in muscle and liver. The term of glycogen was coined in the 1850s by French physiologist Claude Bernard (1813 –1878) who also defined the term “milieu intérieur” (homeostasis). In 1855 he coined the term ‘matière glycogene’ — sugar-making material. Bernard believed that glycogen is formed by proteins. In 1903 Grude proved that carbohydrates form glycogen in the artificially perfused liver and later in numerous experiments on rabbits Barrenscheen obtained formation of glycogen in the isolated liver by 2% solution of glycose. Additionally, in 1909 de Meyer proved that pancreas is necessary for glycogen formation in the liver. Von Gierke  first  described patient with glycogen storage disease  in 1929.

Definition

Glycogen is a branched polymer of glucose residues (polysaccharite) which is analogous to the starch in plants which is a single linear chain of glucose,. Glycagon can be broken down to glucose molecules when energy is needed.