What does phosphorylation mean?
Phosphorylation is the chemical process of adding a phosphate group to a molecule. In living cells, it usually means the transfer of phosphate from ATP to a target such as a protein, lipid, or carbohydrate. Because adding this charged group can change a molecule's shape, charge, stability, or interactions, phosphorylation often acts as a molecular switch: it may activate a protein, inhibit it, or alter where and when it operates. The process is central to metabolism, cell signaling, DNA replication, and the cell cycle, and it is commonly regulated by enzymes called kinases. The reverse reaction, in which a phosphate group is removed, is called dephosphorylation and is usually catalyzed by phosphatases. In scientific and medical writing, phosphorylation is therefore more than a chemical modification; it is a widely used mechanism for controlling biological activity.
nounThe chemical process of adding a phosphate group to a molecule. In biochemistry, it usually refers to the enzyme-mediated transfer of a phosphate group from ATP to a protein, lipid, or other target, thereby altering the target's activity or function.
- The biochemical process of adding a phosphate group to a molecule, usually by transferring it from ATP to a biological target.
"Kinase-mediated phosphorylation can switch a protein's activity on or off."
"Kinase-mediated phosphorylation can switch a protein's activity on or off."
"The treatment increased phosphorylation of the receptor, setting off a downstream signaling cascade."
The plural is grammatically possible but uncommon; the process is usually discussed as an uncountable concept or with modifiers such as “protein phosphorylations.”
"Several distinct phosphorylations were detected after the treatment."
Cells use phosphorylation as a molecular on-off switch, switching proteins into new modes of action with a tiny phosphate tag.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does phosphorylation come from?
Phosphorylation was formed from phosphoryl, a term derived from phosphorus, plus the suffix -ization. Phosphorus comes through Latin from Greek phōs, meaning “light,” and phoros, meaning “bearing,” a reference to the element's glow when exposed to air. Related chemical terms include phosphate, phosphide, and phosphite; in biology, phosphoryl denotes a phosphate-derived group that can be transferred to another molecule.
Related word forms
How phosphorylation is actually used
Technical and usually formal, especially in biochemistry, molecular biology, medicine, and pharmacology. In biological contexts, the process is commonly contrasted with dephosphorylation, the removal of a phosphate group.
Easily confused with phosphorylation
Phosphorylation is the addition of a phosphate group, whereas a phosphatase is an enzyme that catalyzes its removal.