1.6) Discuss Mitchell’s chemiosmotic hypothesis of ATP generation in mitochondria (discuss the roles of the electron transport chain, proton gradient and ATP synthase complex).
The chemiosmotic hypothesis was proposed by Peter Mitchell. This hypothesis stated that a proton-motive force was responsible for driving the synthesis of ATP. In this hypothesis, protons would be pumped across the inner mitochondrial membrane as electrons went through the electron transfer chain.
The proton gradient produced by proton pumping during the electron transport chain is used to synthesize ATP. Protons flow down their concentration gradient into the matrix through the membrane protein ATP synthase, causing it to spin (like a water wheel) and catalyze conversion of ADP to ATP.