Final answer:
When the net charge on either side of the plasma membrane is zero, the electrochemical potential across the membrane is zero, which means that there is no net movement of ions due to charge or concentration gradients. This is distinct from the resting membrane potential, typically around -70 mV, which is crucial for the function of neurons and muscle cells.
Step-by-step explanation:
When the net charge on either side of the plasma membrane is zero, it indicates that the electrochemical potential across the membrane is zero. This means that there is no net force driving the movement of ions across the membrane due to a difference in electrical charge or chemical (concentration) gradient. However, it is important to distinguish this state from the resting membrane potential, which is characterized by a difference in charge across the membrane.
The resting membrane potential is typically around -70 mV, with the inside of the cell being negatively charged relative to the outside. This is primarily due to the differing permeability of the membrane to various ions, especially potassium (K+) and sodium (Na+), and the activity of the sodium-potassium pump, which moves two K+ ions into the cell and three Na+ ions out of the cell for each ATP molecule consumed. The resting membrane potential is crucial for the function of neurons and muscle cells, among others.
When considering the multiple choice options provided in the question, the correct statement pertaining to a net charge of zero would be: C) The electrochemical potential across the membrane is zero. The other options are not necessarily true when the net charge is zero.