the tendency of substances to diffuse from regions of higher concentration. He went on to show that ATP synthesis was coupled to this electrochemical gradient. His hypothesis was confirmed by the discovery of ATP synthase, a membrane-bound protein that uses the potential energy of the electrochemical gradient to make ATP; and by the discovery by André Jagendorf that a pH difference across the thylakoid membrane in the chloroplast results in ATP synthesis. Protonmotive Q-cycle Later, Peter Mitchell also hypothesized some of the complex details of electron transport chains. He conceived of the coupling of proton pumping to quinone-based electron bifurcation, which contributes to the proton motive force and thus, ATP synthesis. Awards and honours In 1978 he was awarded the Nobel Prize in Chemistry "for his contribution to the understanding of biological energy transfer through the formulation of the chemiosmotic theory." He was elected a Fellow of the Royal Society (FRS) in 1974. References External links 1920 births 1992 deaths People from Mitcham English biochemists Alumni of Jesus College, Cambridge British biochemists Nobel laureates in Chemistry People educated at Queen's College, Taunton British Nobel laureates Recipients of the Copley Medal Academics of the University of Edinburgh Fellows of the Royal Society Foreign associates of the National Academy of Sciences English Nobel laureates Independent scholars Scientists from Cornwall