Describe and unstimulated resting cell.
There are more anions (negative ions) on the inside of the plasma membrane than on the outside. The plasma membrane is electrically polarized (charged). There are excess sodium ions (Na+) in the extracellular fluid (ECF). There are excess potassium ions (K+) in the intracellular fluid (ICF). Also in the ICF, there are anions such as proteins, nucleic acids, and phosphates that cannot penetrate the plasma membrane. These anions make the inside of the plasma membrane negatively charged by comparison to its outer surface.