Question

GHK: Resting Membrane Potential Let's take $P_K:P_{Na} = 1:0.04$ for a neuron at rest, $V_{rest} = \frac{RT}{F} ln \frac{p_K[K]_o + p_{Na}[Na]_o}{p_K[K]_i + p_{Na}[Na]_i}$ $= 58log \frac{p_K/p_{Na} [K]_o + [Na]_o}{p_K/p_{Na} [K]_i + [Na]_i}$ $= 58log \frac{253 + 145}{25140 + 18} = 58log \frac{220}{3518}$ $= 58 \times (-1.2)$ $= -70 mV

          GHK: Resting Membrane Potential
Let's take $P_K:P_{Na} = 1:0.04$ for a neuron at rest,
$V_{rest} = \frac{RT}{F} ln \frac{p_K[K]_o + p_{Na}[Na]_o}{p_K[K]_i + p_{Na}[Na]_i}$
$= 58log \frac{p_K/p_{Na} [K]_o + [Na]_o}{p_K/p_{Na} [K]_i + [Na]_i}$
$= 58log \frac{25*3 + 145}{25*140 + 18} = 58log \frac{220}{3518}$
$= 58 \times (-1.2)$
$= -70 mV

GHK: Resting Membrane Potential
Let's take PK:PNa = 1:0.04 for a neuron at rest,
Vrest = (RT)/(F) ln (pK[K]o + pNa[Na]o)/(pK[K]i + pNa[Na]i)
= 58log (pK/pNa [K]o + [Na]o)/(pK/pNa [K]i + [Na]i)
= 58log (25*3 + 145)/(25*140 + 18) = 58log (220)/(3518)
= 58 × (-1.2)
= -70 mV

Added by Ashley S.

Biology for AP Courses

Julianne Zedalis, John Eggebrecht

Instant Answer

Solved by Expert Derrick Danso

04/19/2022

Step 1

The equation is: V = RT * (P[K+] * [K+]o + P[Na+] * [Na+]o) / (F * (P[K+] + P[Na+])) where V is the resting membrane potential, R is the gas constant, T is the temperature in Kelvin, P[K+] and P[Na+] are the permeabilities of potassium and sodium ions, [K+]o and Show more…

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Thanks for your feedback!

I am confused about how my professor solved this. I don't need an answer but more of an explanation. GHK: Resting Membrane Potential Let's take Pk:PNa = 1:0.04 for a neuron at rest, RT pk[K]+ pNa[Na]o / F Rk[K]+ RNa[Na] Rk/pNa[K]+[Na] = 58loa Rk/pNa[K]+[Na] 25*3 + 145 = 58loa 25*140+ 18 220 : 58loa 3518 = 58 x (-1.2) = -70 mV