The Nernst equation can be used to calculate the membrane potential based on the ratio of the outer and inner ion concentration.In a resting cell, membrane potential is calculated taking only K⁺ ions into account.What is V when C_o = 15 mM and C_i = 106 mM?

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Quizplus · Accepted Answer

The Nernst equation for potassium (K+) at body temperature (approximately 37°C) is given by $V = \frac{RT}{zF} \ln\left(\frac{[K^+]_{out}}{[K^+]_{in}}\right)$, where R is the gas constant, T is the temperature in Kelvin, z is the charge of the ion (which is +1 for K+), F is Faraday's constant, and $[K^+]_{out}$ and $[K^+]_{in}$ are the external and internal potassium ion concentrations, respectively. Using the given concentrations, the equation simplifies to calculate the resting membrane potential, which typically results in a negative value for cells due to the higher internal concentration of potassium ions compared to the external environment. This leads to a value around -52.7 mV, which is consistent with the typical resting membrane potential of many cells.

The Nernst Equation Can Be Used to Calculate the Membrane