Final answer:
The generation of a membrane potential involves the leaking of potassium and sodium ions through the cell membrane and the action of the sodium-potassium pump, which maintains this potential by moving ions against their concentration gradients.
Step-by-step explanation:
To understand the generation of a membrane potential, one must first recognize that both potassium (K+) and sodium (Na+) ions can leak through the cell membrane by diffusion. However, it is essential to note that in the polarized state of the cell membrane, sodium and potassium ion concentrations are not in static equilibrium due to the constant activity of the sodium-potassium pump.
The sodium-potassium pump ensures the maintenance of the membrane potential, but not exclusively through diffusion processes. It uses energy to move three sodium ions out of the cell in exchange for two potassium ions entering the cell. This active transport process contributes to the membrane potential by creating a negative charge inside the cell relative to the outside.
Finally, the statement that, 'When the sodium-potassium pump is activated, potassium is pumped into the cell twice as fast as the sodium is pumped out, thus causing the membrane potential,' is incorrect. The correct ratio is three sodium ions out for every two potassium ions in, which helps to maintain the resting membrane potential.