Turning a molecular wheel with a flow of protons

(image source)

A scientist's story of first hearing Peter Mitchell's proposal that a concentration gradient of protons was the energy source for ATP synthase. I recommend reading this starting in the middle, with "In 1955..." (highlighted, second sentence of the 3rd paragraph) and then looping back to the beginning of the article afterwards.

"I remember thinking... that I would bet anything that ATP synthesis didn’t work that way."

Mitchell was an unusual scientist:

"For much of his career he worked in his own lab in a... house... his research funded in part by a herd of dairy cows." (source)

In this video, see how ATP synthase works with key molecular details gained in part from solving protein structures in different states (ATP-bound, ADP-bound states etc) mostly from John Walker's lab in Cambridge, England. Walker shared the Nobel Prize for deciphering the structure of ATP synthase.