If, hypothetically, the concentration gradients and the permeability of 2 different ions (Na+ and K+ for example) in 2 separate solutions are the same, will the diffusion potentials be different? I'm trying to gain an intuition for the concept of diffusion potential and equilibrium potential. It read this topic from 2 physiology textbooks but haven't really found an answer anywhere. I understand that the diffusion potential is the potential difference generated when an ion moves through a membrane down its concentration gradient. I also know that it is determined by both the concentration gradient and the permeability, but, does the type of ion itself matter if the charge on the ions is the same?


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You can determine the diffusion potential mathematically with the Nernst equation. If it's not in the Nernst equation, it's not necessary.

The charge of the ion matters (including valance), the temperature matters. Some universal constants are in the equation but these don't vary.

Other factors that potentially matter are found in the other parameters, like the permability.


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