Chemicalb asisf or the largef ree-energyc hangea ssociatedw
ith ATPh ydrolysis@. fne charges eparationth at results
from hydrolysirse lievees lectrostatirce pulsiona mongt hef our negativec
hargeso n ATP@. ftre producti norganicp hosphat(eP i)i s stabilizedb
y formationo f a resonanchey brid,i n whiche acho f thef our
phosphorus-oxygebno nds has the samed egreeo f double-bond
charactear nd the hydrogenio n is not permanentlays sociatewd ith
anyo neo f theo xygens(.S omed egreeo f resonancset abilizatioanl so
occursi n phosphateisn volvedi n estero r anhydrideli nkagesb, ut
fewer resonancefo rmsa re possiblet han for P,.)O fne product
ADP2 immediatelyio nizes,r eleasinga protoni nto a mediumo f
very low [H*l (pH 7). A fourth factor (not shown) that favors ATp hydrolysisis
t he greatedr egreeo f solvation(h ydrationo)f the products
P;a ndA DP relativeto ATP,w hichf urthers tabilizetsh e productsre lative
to the reactants