The equilibrium potential of K⁺ ions in nerve cells is about -90 mV. The membrane potential of typical nerve cells at rest is -70 mV. Therefore A) Increasing the permeability of a resting neuronal membrane to K⁺ will make the membrane potential more negative inside with respect to outside. B) In resting neurons, there is a net diffusion of K⁺ into the cell. C) changing the resting membrane potential of a neuron to -80 mV would increase K⁺ diffusion rate out of the cell. D) potassium is the only permanent ion at rest. E) there must be another permanent ion with an equilibrium potential more negative than -90 mV.

Question

Quizplus · Accepted Answer

The equilibrium potential of K⁺ ions is more negative than the resting membrane potential. Therefore, increasing the permeability of the membrane to these ions will lead to an influx of negatively charged ions, making the membrane potential more negative inside with respect to outside. Option B is incorrect because the membrane potential at rest is negative, and there is no net diffusion of positively charged ions into the cell. Option C is incorrect because changing the resting membrane potential to -80 mV will not change the equilibrium potential of potassium ions, so there will be no effect on the diffusion rate of potassium ions out of the cell. Option D is incorrect because there are other ions present in the resting membrane potential, such as sodium and chlorine. Option E is incorrect because the equilibrium potential of potassium ions (-90 mV) is already more negative than the resting membrane potential (-70 mV), which means there is no need for another ion with a more negative equilibrium potential.

The Equilibrium Potential of K+ Ions in Nerve Cells Is

The Equilibrium Potential of K⁺ Ions in Nerve Cells Is