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Phosphorolysis is the cleavage of a compound in which inorganic 
In addition, sometimes phosphorolysis is preferable to hydrolysis (like in the breakdown of glycogen or
phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid .
The phosphate or orthophosphate ion is derived from pho ...
is the attacking group. It is analogous to hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile.
Biological hydrolys ...
.Stryer, L. (1988) Biochemistry, 3rd ed., Freeman (p. 451)
An example of this is glycogen
Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. The polysaccharide structure represents the main storage form of glucose in the body.
Glycogen functions as one o ...
breakdown by glycogen phosphorylase, which catalyzes attack by inorganic phosphate on the terminal glycosyl residue at the nonreducing end of a glycogen
Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. The polysaccharide structure represents the main storage form of glucose in the body.
Glycogen functions as one o ...
molecule. If the glycogen chain has ''n'' glucose units, the products of a single phosphorolytic event are one molecule of glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...
1-phosphate and a glycogen chain of ''n''-1 remaining glucose units.
In addition, sometimes phosphorolysis is preferable to hydrolysis (like in the breakdown of glycogen or starch
Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human d ...
, as in the example above) because glucose 1-phosphate yields more ATP than does free glucose when subsequently catabolized to pyruvate
Pyruvic acid (CH3COCOOH) is the simplest of the alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate, the conjugate base, CH3COCOO−, is an intermediate in several metabolic pathways throughout the cell.
Pyruvic ac ...
.
Another example of phosphorolysis is seen in the conversion of glyceraldehyde 3-phosphate to 1,3-bisphosphoglycerate in glycolysis. The mechanism involves phosphorolysis.
See also
*Phosphorylase
In biochemistry, phosphorylases are enzymes that catalyze the addition of a phosphate group from an inorganic phosphate (phosphate+ hydrogen) to an acceptor.
:A-B + P A + P-B
They include allosteric enzymes that catalyze the production of gluc ...
References
External links
* Chemical processes {{Reaction-stub