Final answer:
The two ions primarily responsible for stabilizing the resting membrane potential are sodium (Na+) and potassium (K+). These ions are maintained at different concentrations inside and outside the cell by sodium-potassium pumps, which are critical for resting membrane potential maintenance.
Step-by-step explanation:
The two ions that are primarily responsible for stabilizing the resting membrane potential are sodium and potassium. Potassium ions (K+) are the major intracellular cations and are more concentrated inside the cell. Sodium ions (Na+), conversely, are more concentrated outside the cell. The sodium-potassium pumps in cell membranes continuously work to pump potassium in and sodium out of the cell, thus maintaining the necessary ion gradient. The pump actively transports three sodium ions out and brings two potassium ions in, which is an energy-consuming process using ATP.
During the resting state of a cell, the membrane is permeable to K+ ions and less so to Na+ ions. Potassium ions thus diffuse out of the cell more freely, causing the inside of the cell to become negatively charged relative to the outside. This leads to the establishment of the resting membrane potential. Sodium and potassium work closely in this process; without their movement and the action of the sodium-potassium pumps, the resting membrane potential could not be maintained.