Practice question · Multiple choice
A neuron at rest sits at about −70 mV. Why is the membrane NOT electrically neutral at rest?
Hints
- Ask what a voltage across a membrane physically is.
- A charged battery is not neutral either.
Show the answer
C. Because the potential is a separation of charge across the membrane
Why
The resting potential IS a charge separation, maintained at metabolic cost. The cell is a charged capacitor waiting to discharge, and calling it neutral removes the mechanism.
Practise Resting Potential
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More questions on Resting Potential
- Sort each ion by where it is more concentrated across the membrane of a resting neuron.
- Trace WHY the inside of the resting neuron ends up negative. Put the causal steps in order.
- A neuron's potassium equilibrium potential is about −90 mV, yet the membrane actually rests at about −70 mV.…
- Select every statement that is TRUE of the resting potential.
- The sodium-potassium pump runs constantly in every neuron, and the brain spends a large share of its entire…