Question

What is the equilibrium potential (Ek) for chloride ion across the cell membrane at T= 310 degree Kelvin. Formula and additional information is given below:

R = 8.314 J mol-1 K-1
F = 96,485 Cmol-1
T = 310 K
z = -1
The given chloride concentration is 10 times higher outside the cell than in the cytosol.
Ek = 2.303 (RT/zF) Log10 ([Chl] / [Chl])
Log10 (10) = 1

Answer 1

The equilibrium potential (Ek) for chloride ions (Cl-) at 310 K is approximately -0.0415 V, calculated using the Nernst equation with given physiological constants and a tenfold difference in ion concentration across the cell membrane.

Step-by-step explanation:

The question asks about calculating the equilibrium potential (Ek) for chloride ions (Cl-) across a cell membrane at a temperature of 310 Kelvin using the Nernst equation. Given the valence (z) of chloride ion as -1, the universal gas constant (R) as 8.314 J mol-1 K-1, the Faraday's constant (F) as 96,485 C mol-1, and the tenfold higher concentration of Cl- outside the cell compared to inside, we can apply the Nernst equation Ek = (2.303 (RT/zF)) * Log10 ([Cl-]outside / [Cl-]inside). Since Log10(10) = 1, we can simplify the equation further.

Substitute the known values into the equation:
Ek = (2.303 (8.314 J mol-1 K-1 * 310 K / -1 * 96,485 C mol-1)) * Log10 (10)
Ek = - (2.303 * 0.018 V) * 1
Ek = -0.0414543 V

Therefore, the equilibrium potential for Cl- is approximately -0.0415 V.