Nernst equation for potassium equilibrium potential

This gives the membrane voltage at which potassium ions are in electrochemical equilibrium across a cell membrane, so there is no net potassium flow. It is used in neuroscience and physiology to estimate the resting membrane potential contribution from potassium.

E_{e q, K^{+}} = \frac{R T}{z F} ln \frac{[ K ^{+} ] _{o}}{[ K ^{+} ] _{i}}

E_{eq,K^+} = \frac{RT}{zF} \ln \frac{[K^+]_{o}}{[K^+]_{i}}

What the symbols mean

$E_{e q, K^{+}}$	equilibrium (Nernst) potential for potassium ions, in volts
$R$	molar gas constant, 8.314 J·mol^{-1}·K^{-1}
$T$	absolute temperature, in kelvin
$z$	charge number of the ion (+1 for K^+)
$F$	Faraday constant, about 96485 C·mol^{-1}
$[K^{+}]_{o}$	extracellular potassium concentration
$[K^{+}]_{i}$	intracellular potassium concentration

About this formula

FieldBiology and medicine
TopicElectrophysiology
LevelUniversity
Also calledNernst potential for potassium, potassium equilibrium potential, potassium reversal potential, Nernst equation potassium, membrane potential potassium, nernst equation
SourceWikidata Q389844

Write it in Obsidian

MathLive is a free visual math editor for Obsidian. Run Find a formula, type “nernst equation for potassium equilibrium potential”, and it goes into your note as editable LaTeX. You can also scan formulas from screenshots, PDFs and handwriting.

Get MathLive for Obsidian See how it works

What the symbols mean

About this formula

Write it in Obsidian

Related formulas