phospho

Phospho is a chemical prefix used to indicate that a molecule contains a phosphate group or is modified by the addition of a phosphate group. It is widely used in chemistry, biochemistry, and molecular biology to denote phosphate esters, phosphate anhydrides, or phosphorylated derivatives of a compound. In organic chemistry, phospho- appears in terms such as phosphomonoesters, phosphodiesters, and phosphoanhydrides; many biomolecules carry phosphate groups, including nucleotides, nucleic acids, lipids, and proteins.

In biology, phosphorylation is a key regulatory mechanism. Kinases transfer a phosphate from ATP to specific amino acid residues—primarily serine, threonine, and tyrosine—on target proteins, creating phosphoproteins that may alter activity, interactions, localization, or stability. Dephosphorylation by phosphatases reverses these effects. Phosphorylation is central to signaling pathways, cell cycle control, metabolism, and neurotransmission. Phosphate groups are also relevant in energy metabolism, as in ATP and other nucleotides, where phosphoanhydride bonds store usable energy.

In nutrition and medicine, phosphate groups are part of major biomolecules such as DNA, RNA, ATP, phospholipids, and many enzymes. The term phospho appears in research fields like phosphoproteomics, e.g., mapping phosphorylation sites, and in the naming of phosphorylated drugs and diagnostics.

Overall, phospho denotes phosphate-related functionality in molecules; its specific meaning depends on context, ranging from a structural descriptor in chemical nomenclature to a functional modification in cellular signaling.