Chapter 33.2, Problem 2TYK

The resting membrane potential occurs because

1. the membrane is leaky to ${\text{Na}}^{+}$ and ${\text{K}}^{+}$.
2. the concentrations of ${\text{Na}}^{+}$ and ${\text{K}}^{+}$ are unequal across the membrane.
3. the ${\text{Na}}^{+}/{\text{K}}^{\text{+}}$ ATPase pump moves two ${\text{K}}^{+}$ into the cell for every three ${\text{Na}}^{+}$ it moves out of the cell.
4. a and b are correct.
5. a, b, and c are all correct.