Outline the processes involved in the generation of ATP through chemiosmosis (6 marks)

Reduced NAD and FAD from the Krebs cycle are re-oxidised in the electron transport chain, situated on the inner mitochondrial membrane. The electrons are passed down the protein complexes embedded in the electron transport chain and the hydrogen ions are actively pumped out of the mitochondrial matrix into the intermembrane space via the transmembrane domains present in the cristae, against a concentration gradient. This generates a proton gradient which leads to a proton motive force. This force drives an influx of hydrogen ions from the intermembrane space into the matrix, down a concentration gradient. The hydrogen ions flow through the transmembrane protein ATP synthase and initiates the formation of ATP from ADP and P_i.