Question

Assume you have a membrane with only potassium leakage channels. The RMP is -90mV. Predict the RMP if we add Na+Na+ leakage channels.The most likely RMP value of Na+Na+ is __________.

Answer 1

Adding Na+ leakage channels to a membrane originally with only K+ leakage channels would likely cause the resting membrane potential to shift from -90mV closer to the typical value of -70mV due to the influx of Na+ ions.

Step-by-step explanation:

When a membrane initially has only potassium (K+) leakage channels, the resting membrane potential (RMP) is typically around -90mV. This is due to the higher permeability of the membrane to K+ ions, allowing them to move out of the cell more readily than Na+ ions can move in, creating a net negative charge inside the cell. If we add sodium (Na+) leakage channels to this membrane, more Na+ ions will enter the cell down their concentration gradient, making the inside of the cell less negative.

The most likely resting membrane potential (RMP) value with the presence of Na+ leakage channels will approach the typical neuronal RMP of approximately -70mV. This is because Na+ ions, which are higher in concentration outside the cell, will diffuse into the cell and partially cancel out the negative charge created by the outflow of K+ ions. The sodium-potassium pump helps to maintain this RMP by actively transporting K+ back into the cell and Na+ out of the cell.