What does the Nernst equation help to calculate?

What does the Nernst equation help to calculate?

• A. Cell membrane potential
• B. The equilibrium potential of an ion
• C. Osmolarity of a solution
• D. Transport rate of molecules

Answer: (B)

The Nernst equation is primarily used to calculate the equilibrium potential of specific ions across a cell membrane. This equilibrium potential represents the electrical potential difference that exactly balances the concentration gradient for that particular ion, thus preventing any net movement of the ion across the membrane. The equation takes into account the concentration of the ion inside and outside the cell, allowing for the determination of the voltage at which there is no net flow of that ion in or out of the cell. Understanding this potential is critical in physiology because it helps explain how different ions contribute to the overall membrane potential and how this influences cellular activities, such as action potentials in neurons and muscle cells. While the other options relate to cellular functions, they are not the primary focus of the Nernst equation. The cell membrane potential is influenced by multiple ions and their respective equilibrium potentials, osmolarity pertains to the total solute concentration in a solution, and transport rates are more related to mechanisms like diffusion and active transport. Therefore, the most accurate representation of the Nernst equation's purpose is that it calculates the equilibrium potential of an ion.

The Nernst equation is primarily used to calculate the equilibrium potential of specific ions across a cell membrane. This equilibrium potential represents the electrical potential difference that exactly balances the concentration gradient for that particular ion, thus preventing any net movement of the ion across the membrane.

The equation takes into account the concentration of the ion inside and outside the cell, allowing for the determination of the voltage at which there is no net flow of that ion in or out of the cell. Understanding this potential is critical in physiology because it helps explain how different ions contribute to the overall membrane potential and how this influences cellular activities, such as action potentials in neurons and muscle cells.

While the other options relate to cellular functions, they are not the primary focus of the Nernst equation. The cell membrane potential is influenced by multiple ions and their respective equilibrium potentials, osmolarity pertains to the total solute concentration in a solution, and transport rates are more related to mechanisms like diffusion and active transport. Therefore, the most accurate representation of the Nernst equation's purpose is that it calculates the equilibrium potential of an ion.