What is the Difference Between Nernst Equation and Goldman Equation?

The Nernst equation and the Goldman equation are mathematical expressions used to describe the membrane potential in electrochemical cells, such as cells in biological systems like neurons. The key differences between the two equations are:

Scope: The Nernst equation considers the relationship between membrane potential and standard membrane potential for a single ion, while the Goldman equation combines the Nernst equations for multiple ions to calculate the membrane potential based on their intracellular and extracellular concentrations and the membrane's permeability to these ions.
Reversal Potential: The Nernst equation describes the relationship between membrane potential and standard membrane potential for a single ion, whereas the Goldman equation is a derivative of the Nernst equation and describes the reversal potential, which is the membrane potential at which the net flow of ions is zero.

In summary, the Nernst equation focuses on the relationship between membrane potential and standard membrane potential for a single ion, while the Goldman equation accounts for multiple ions and their concentrations, as well as the membrane's permeability, to calculate the membrane potential and the reversal potential.

On this page

What is the Difference Between Nernst Equation and Goldman Equation?

Comparative Table: Nernst Equation vs Goldman Equation

The Nernst equation and the Goldman equation are both mathematical expressions used to describe the potential of electrochemical cells, but they differ in their focus and applications. Here is a table summarizing the differences between the two equations:

Feature	Nernst Equation	Goldman Equation
Focus	Relationship between membrane potential and standard membrane potential for a specific ion	Reversal potential and membrane permeability
Derivation	Developed by Walther Hermann Nernst	Derived from the Nernst equation by Goldman, Hodgkin, and Katz
Application	Electrochemical cells	Neuronal membranes and ion transporters
Equation	$$E = E^0 + \frac{RT}{zF} \ln \frac{[X]{out}}{[X]{in}}$$	$$ER = E^0R + \frac{RT}{zF} \ln \frac{\sum [X]{out}}{\sum [X]{in}}$$

The Nernst equation is used to explain the relationship between membrane potential and standard membrane potential for a specific ion, while the Goldman equation determines the reversal potential and takes into account the membrane permeability for multiple ions. The Goldman equation is a derivative of the Nernst equation and is particularly useful for studying neuronal membranes and ion transporters.

Guilherme Mazui

Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.