Final answer:
The sodium-potassium pump is responsible for terminating an action potential by restoring the balance of sodium and potassium ions across the cell membrane.
Step-by-step explanation:
The sodium-potassium pump, also known as the Na+/K+ pump, plays a crucial role in terminating an action potential. It is an example of active transport, which uses ATP energy to move ions across the cell membrane against their concentration gradients. The pump moves three sodium ions out of the cell and two potassium ions into the cell, maintaining the concentration differences of these ions that are necessary for bioelectricity.
During an action potential, sodium channels open and sodium ions rush into the cell, causing depolarization. The depolarization triggers the closure of sodium channels and the opening of potassium channels. Potassium ions then leave the cell, causing repolarization and eventually hyperpolarization.
Without the sodium-potassium pump, the concentration of sodium ions inside the cell and potassium ions outside the cell would eventually drop to a point where the cell cannot generate another action potential when stimulated. The pump replenishes these ions to restore the appropriate balance and allow the cell to respond to future stimuli.