 This entire process is called oxidative phosphorylation since ADP is phosphrylated to ATP by using the electrochemical gradient established by the redox reactions of the electron transport chain.Energy obtained through the transfer of electrons down the electron transport chain is used to pump protons from the mitochondrial matrix into the intermembrane space, creating an electrochemical proton gradient (ΔpH) across the inner mitochondrial membrane.This proton gradient is largely but not exclusively responsible for the mitochondrial membrane potential (ΔΨM).