Final answer:
The resting potential of a neuron is approximately -70 millivolts, a state of electrical charge difference across the plasma membrane when no nerve impulse is being transmitted. It is primarily maintained by the sodium-potassium pump and the differential permeability of potassium and sodium ions across the neuron’s membrane.
Step-by-step explanation:
The resting potential of a neuron is the difference in electrical charge across its plasma membrane when it is not actively transmitting a nerve impulse. This voltage is approximately -70 millivolts (mV), with the interior of the cell being more negative relative to the outside. The negative resting membrane potential is created by the action of the sodium-potassium pump which exchanges three Na+ ions outside the cell for two K+ ions inside the cell per ATP molecule consumed, and the higher permeability of the neuron's membrane to potassium ions (K+) compared to sodium ions (Na+).
The resting membrane potential is vital for the function of neurons and muscle cells, with a significant amount of cellular energy dedicated to its maintenance. This charge separation produces a potential difference ranging between -50 to -70 millivolts across the cell membrane, establishing an electric field that is critical for nerve impulse transmission.