Final answer:
The resting membrane potential is typically set at -70 mV, a negative charge inside the cell compared to the outside. This potential is not zero and is maintained by differences in ion concentration between the inside and outside of the cell, particularly due to the permeability of the cell membrane to K+ ions and the action of the Na+/K+ pump.
Step-by-step explanation:
When the net charge on either side of the plasma membrane is zero, this is an equilibrium state where no net movement of ions occurs across the membrane. However, this does not necessarily correspond to any of the options provided. But analyzing the options given:
- There is not necessarily an equal number of K+ ions on each side of the plasma membrane, as the resting membrane potential is maintained by a difference in ion concentration across the membrane.
- K+ leak channels may be open as they allow potassium ions to move down their concentration gradient, contributing to the creation of the resting membrane potential.
- The electrochemical potential across the membrane is not zero; there is an electrochemical gradient due to ion concentration differences.
- The resting membrane potential is typically between -50mV and -70mV for most cells, not as low as -200 mV or as high as -20 mV.
Therefore, the correct statement associated with this scenario is that the resting membrane potential is typically between -50mV and -70mV. This value reflects the difference in ion concentrations maintained by the action of ion pumps and channels.