1. The membrane potential of any living cell is partially the result of:
a) a transient increase in the membrane to sodium conductance
b) a membrane that is leaky to sodium conductance
c) a transient increase in the membrane to potassium conductance
d) a membrane that is leaky to potassium conductance
e) a membrane that is leaky to chloride conductance
2. During the depolarisation phase of an action potential.
Answer (2)
The membrane potential in living cells is primarily determined by the permeability of the membrane to ions, especially potassium. A cell's leaky nature to potassium conductance is central to maintaining a negative resting potential. During the depolarization phase of an action potential, sodium influx occurs, significantly altering the membrane potential. ;
The correct answer is that the membrane potential is maintained by a membrane that is leaky to potassium conductance. This allows potassium ions to exit the cell, which helps maintain a negative resting potential. During depolarization, sodium influx occurs, temporarily altering the membrane potential positively.
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