The leaks and slips of bioenergetic membranes.

Bioenergetic membranes use proton gradients to transduce energy. However, when the proton gradient is large 1) there is a passive leak of protons (and other ions) across these membranes, and 2) some proton pumps may fail to pump protons (a phenomenon known as slip). Leaks and slips may be an unavoidable consequence of membrane structure and cause significant wastage of free energy, but they may also have functional roles beneficial to the organism.