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I need some help understanding how the resting membrane potential is maintained in neurons. I understand that there are more K+ leak channels than Na+ leak channels, meaning that more K+ ions leave the cell membrane than Na+ ions enter.

However, where I am confused is with Na+/K+ ATPase. 3 Na+ are pumped out and 2 K+ are pumped in. From what I understand, this pumps out Na+ as fast as it leaks in. But if K+ leak out faster and less are brought in, then won't there be eventually no K+ left in the cell?

Monya Feldman
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    Better to not worry about the pump ratios at all. They don't matter appreciably. Learn and use the Goldman/GHK equation. – Bryan Krause Jul 04 '21 at 23:28
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    Think of it this way, the rate at which K+ and Na+ try to leak to the side with the least concentration of that ion is counteracted by NA+/K+ pump. So while K+ is leaking out and Na+ is leaking in, this process is balanced by the pump (pumping K+ in and Na+ out). This is process will come to a balanced equilibrium, where ions will still be leaking, and still being pumped, but the net sum of these two opposing processes is zero change in concentration. – xelo747 Jul 12 '21 at 09:07

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