The nonpolar core of the membrane of a muscle cell has a thickness d = 4nm and a dielectric constancy k = 20. (a) What is the surface capacity of the membrane? Express your response in microcoulombs per square centimeter. (b) During muscle contraction, the internal potential of the cell increases by about 100 mV. For 1 cm2 of membrane, how many Na+ ions must have entered the cell for this purpose? (c) The medium outside the cell initially contains 0.150 mol / L of Na + ions in solution. Considering that it extends to 1 µm from the cell, what is the decrease in Na+ concentration immediately after the change in potential? (d) Estimate the number of times the process can be repeated before the Na+ ion reserve is exhausted.

The nonpolar core of the membrane of a muscle cell has a thickness d = 4nm and a dielectric constancy k = 20. (a) What is the surface capacity of the membrane? Express your response in microcoulombs per square centimeter. (b) During muscle contraction, the internal potential of the cell increases by about 100 mV. For 1 cm2 of membrane, how many Na+ ions must have entered the cell for this purpose? (c) The medium outside the cell initially contains 0.150 mol / L of Na + ions in solution. Considering that it extends to 1 µm from the cell, what is the decrease in Na+ concentration immediately after the change in potential? (d) Estimate the number of times the process can be repeated before the Na+ ion reserve is exhausted.

College Physics

10th Edition

ISBN:9781285737027

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter9: Solids And Fluids

Section: Chapter Questions

Problem 4WUE

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