Phosphorolysis is the
cleavage of a compound in which inorganic
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 phosph ...
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 breakdown by glycogen phosphorylase, which catalyzes attack by inorganic phosphate on the terminal glycosyl residue at the nonreducing end of a
glycogen 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, as in the example above) because glucose 1-phosphate yields more ATP than does free glucose when subsequently
catabolized to
pyruvate.
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 gluco ...
References
External links
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Chemical processes
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