The beauty of chemiosmotic coupling is that it transcends chemistry. It allows cells to save up ‘loose change’. If it takes 10 protons to make 1 ATP, and a particular chemical reaction only releases enough energy to pump 4 protons, then the reaction can simply be repeated 3 times to pump 12 protons, 10 of which are then used to make 1 ATP. While this is strictly necessary for some forms of respiration, it is beneficial for all of us, as it allows cells to conserve small amounts of energy that would otherwise be wasted as heat. And that, almost always, gives proton gradients an edge over plain
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