<P> This was a radical proposal at the time, and was not well accepted . The prevailing view was that the energy of electron transfer was stored as a stable high potential intermediate, a chemically more conservative concept . The problem with the older paradigm is that no high energy intermediate was ever found, and the evidence for proton pumping by the complexes of the electron transfer chain grew too great to be ignored . Eventually the weight of evidence began to favor the chemiosmotic hypothesis, and in 1978, Peter Mitchell was awarded the Nobel Prize in Chemistry . </P> <P> Chemiosmotic coupling is important for ATP production in mitochondria, chloroplasts and many bacteria and archaea . </P> <P> The movement of ions across the membrane depends on a combination of two factors: </P> <Ol> <Li> Diffusion force caused by a concentration gradient - all particles tend to diffuse from higher concentration to lower . </Li> <Li> Electrostatic force caused by electrical potential gradient - cations like protons H tend to diffuse down the electrical potential, from the positive (P) side of the membrane to the negative (N) side . Anions diffuse spontaneously in the opposite direction . </Li> </Ol>

Which of the following occurs during chemiosmosis in a mitochondrion