Resting membrane potential (RMP) is the difference in the electric potential across a cell membrane when the cell is unstimulated or in a state of rest. The RMP is produced and maintained by a combination of mechanisms. 

• Ion Distribution: The uneven distribution of ions (charged particles) across the cell membrane plays a key role in determining RMP. The outside of the cell has higher concentrations of Na+ (sodium), while the inside of the cell has high concentrations of K+ (potassium).
• Selective Permeability: The cell membrane is selectively permeable, allowing more K+ to leak out of the cell than Na+ to leak in, primarily through K+ leak channels.
• Sodium-Potassium Pump: This active transport mechanism uses ATP to actively pump 3 Na+ ions out of the cell and 2 K+ ions into the cell, against their electrochemical gradients. This maintains the negative environment inside the cell, which helps maintain the resting potential. If the sodium-potassium pump shuts down, the concentration gradients will dissipate and so will the RMP. 
• Negatively Charged Proteins: Large, negatively charged proteins inside the cell contribute to the negative charge within the cell.