The potential across a cell membrane of thickness 0.5 ìm increases by 75 mV from inside to outside. What is the surface charge density on the outside surface of the membrane?

Question

Quizplus · Accepted Answer

The potential difference (V) across a membrane is related to the surface charge density (σ) by the equation V = σd/ε₀, where d is the thickness of the membrane and ε₀ is the permittivity of free space. Rearranging gives σ = Vε₀/d. Substituting V = 75 mV = 75 x 10⁻³ V, d = 0.5 x 10⁻⁶ m, and ε₀ = 8.85 x 10⁻¹² C²/N·m², we find σ = 1.5 μC/m².

The Potential Across a Cell Membrane of Thickness 0