Examkrackers resting membrane potential question

[frodo25]

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On pg 47 of EK I am confused about questions 27 and 30. 27 says that if the membrane becomes impermeable to K+ but the Na+/K+ remains functional, then the resting potential becomes more positive due to increase of K+ inside the cell.
BUT, I thought the Nerst Eqn says that an increase in intracellular K+ makes the resting potential more negative. How can both be true?

 

[basophilic]

Nernst equation provides information about equilibrium potential, which means ions are allowed to equilibrate either side of the membrane such that no more net movement occurs. If you make membrane impermeable to K+ (i.e. plug the leak channels), K+ can't equilibrate across the membrane. So you can't use Nernst Equation here. (Also, the Na/K ATPase will probably encounter greater difficulty in functioning than with the normal membrane)
Hence, increased presence of K+ leads to increase in potential inside the cell

 

[To be MD]

Nernst equation provides information about equilibrium potential, which means ions are allowed to equilibrate either side of the membrane such that no more net movement occurs. If you make membrane impermeable to K+ (i.e. plug the leak channels), K+ can't equilibrate across the membrane. So you can't use Nernst Equation here. (Also, the Na/K ATPase will probably encounter greater difficulty in functioning than with the normal membrane)
Hence, increased presence of K+ leads to increase in potential inside the cell

Was just about to post this question. Thank you