author | home
H3PO4, a.k.a., phosphoric acid.
That is, the Pi in ATP → ADP + Pi, where the overall reaction is ATP hydrolysis. Alternatively, Pi in the endergonic reaction, ADP + Pi → ATP. Inorganic phosphate is simply a phosphate group that is no longer a functional group because it is no longer tethered..
Note that at physiological, that is, neutral pHs, phosphoric acid is normally found in an ionized form, that is, as a combination of H2PO4- and HPO42-.
For more on this topic, see Wikipedia and Google. Contact web master. Return to home.