Final answer:
The development of an electrochemical gradient is established by the directional pumping of protons during electron transport, leading to the processes of chemiosmosis and oxidative phosphorylation for ATP synthesis.
Step-by-step explanation:
While electron transport is occurring, the development of a proton gradient is established by the directional pumping of protons across the inner membrane of the mitochondrion. This gradient is actually an electrochemical gradient, which is formed due to both the concentration difference of protons, creating a pH gradient, and the electrical difference due to the positive charge of the protons.
The energy from the electron transport chain is used to pump hydrogen ions (protons) across the membrane. As a result of this pumping, there is an uneven distribution of H+ ions across the membrane, thus establishing the electrochemical gradient.