Phosphorylation

In biochemistry, phosphorylation is described as the "transfer of a phosphate group" from a donor to an acceptor.^[1] A common phosphorylating agent (phosphate donor) is ATP and a common family of acceptor are alcohol (chemistry)s:

[Adenosyl−O−PO₂−O−PO₂−O−PO₃]⁴⁻ + ROH → Adenosyl−O−PO₂−O−PO₃H]²⁻ + [RO−P−O₃]²⁻

This equation can be written in several ways that are nearly equivalent that describe the behaviors of various protonated states of ATP, ADP, and the phosphorylated product. As is clear from the equation, a phosphate group per se is not transferred, but a phosphoryl group (PO₃^-). Phosphoryl is an electrophile.^[2] This process and its inverse, dephosphorylation, are common in biology.^[3] Protein phosphorylation often activates (or deactivates) many enzymes.^[4][5]