The difference in electric potential between the interior and exterior of a biological cell is termed the

The difference in electric potential between the interior and exterior of a biological cell is termed the

• A. Membrane potential
• B. Current
• C. Gradient
• D. Voltage

Answer: (A)

Membrane potential is the electrical difference across the cell membrane, created by ions distributed unevenly on the two sides and by the membrane’s selective permeability. In resting cells the inside is typically negative relative to the outside, producing a resting membrane potential often around -70 mV in many neurons. This potential arises mainly from the membrane being more permeable to potassium than to other ions and from the Na+/K+-ATPase pump maintaining the ion gradients. The term voltage is a general way to describe potential difference, but for a cell across its membrane the specific term is membrane potential. Current refers to the actual flow of charges, not the stored difference, and a gradient here would imply a concentration gradient rather than the electrical potential across the membrane. So the difference in electric potential across the cell membrane is best described as the membrane potential.

Membrane potential is the electrical difference across the cell membrane, created by ions distributed unevenly on the two sides and by the membrane’s selective permeability. In resting cells the inside is typically negative relative to the outside, producing a resting membrane potential often around -70 mV in many neurons. This potential arises mainly from the membrane being more permeable to potassium than to other ions and from the Na+/K+-ATPase pump maintaining the ion gradients. The term voltage is a general way to describe potential difference, but for a cell across its membrane the specific term is membrane potential. Current refers to the actual flow of charges, not the stored difference, and a gradient here would imply a concentration gradient rather than the electrical potential across the membrane. So the difference in electric potential across the cell membrane is best described as the membrane potential.