The chemiosmotic theory was proposed by Peter Mitchell in 1961 and describes how ATP is generated in the mitochondria and chloroplasts. According to this theory, the energy from electron transfer through the electron transport chain is used to pump protons across a membrane, creating a proton gradient. This gradient drives the synthesis of ATP from ADP and inorganic phosphate via ATP synthase, a process known as oxidative phosphorylation in mitochondria and photophosphorylation in chloroplasts.
