Abstract
The puzzling results of 18O‐exchange experiments churned in Paul Boyer's mind, and he realized that the proton‐motive force generated upon oxidative phosphorylation is not used primarily for the synthesis of an ATP molecule, but instead its release. The concept of the binding change mechanism was born. For the formation of ATP from ADP and inorganic phosphate—one of the most important reactions in nature—catalysis by ATP synthase requires sequential conformational changes and a rotary mechanism that drives these changes; this enzyme is truly a remarkable molecular machine.