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A

Anonymous

Oct 14, 2024

Physics Problem (membrane diffusion)?

Living cells actively transport singly ionized sodium ions (Na⁺) from the inside of the cell to the outside in order to maintain a membrane potential, defined as ΔV_membrane = V_in − V_out = -70 mV. This process is often referred to as "pumping" because work must be performed to move a positively charged ion from the negatively charged interior of the cell to the positively charged exterior. Additionally, this process must occur continuously since sodium ions tend to "leak" back into the cell through diffusion.

A) How much work must be done to move one sodium ion from the inside of the cell to the outside?

W = ???

1 Answers

A
Anonymous

Jan 14, 2025

A) W = |q||ΔV| = 1.6×10^-19 x 0.070 = 1.05X10^-20 J

B) In one second, pumping N sodium ions uses 15J so:

N = 15/(1.05X10^-20) = 1×10^21 (to 1 sig. fig.)

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