Final answer:
The inside of a typical cell, being negative, attracts extracellular cations due to the electrochemical gradient across the plasma membrane. The combined effects of the cell's internal negative charge and the ions' concentration gradients drive cations, specifically Na+ and K+, to move inward.
Step-by-step explanation:
Based solely upon its electrical charge, the inside of a typical cell will tend to attract extracellular cations to move inward. This is due to the electrochemical gradient that exists across the plasma membrane. The interior of cells is negative compared to the positive extracellular fluid, and thus positive ions, or cations, are attracted into the cell.
Electrochemical gradients are the combined effect of concentration gradients, which reflect the differential concentrations of ions across the membrane, and electrical gradients, which reflect the difference in charge. The membrane potential created by these gradients favors the movement of cations, such as Na+ and K+, towards the interior's negativity. While sodium (Na+) has a higher concentration outside the cell, potassium (K+) ions have a higher concentration inside the cell.
Due to the negative charge inside cells, caused by negatively charged proteins and other negatively charged molecules, an exhibited electrical force drives cations into the cell. This force, coupled with the chemical force from the concentration gradient, creates an electrochemical gradient that significantly influences ion movement, particularly relevant to muscle and nerve cells.