Video explanation
A sliding divider switches between a protein surface and a mechanical cutaway. Protons crossing the membrane drive a rotor linked to ATP production.
Energy from a proton gradient
An electrochemical gradient across the membrane drives proton movement through F₀, coupled to rotation.
Rotation changes binding sites
The shaft changes conformations in F₁ catalytic sites, enabling ADP and phosphate binding, ATP formation and release.
A protein, not a metal machine
The machine half explains coupling. Real molecules also undergo thermal motion and molecular interactions, and proton-to-ATP ratios vary by structure.