Cell Membranes and Dielectrics
Many cells in the body have a cell membrane whose inner andouter surfaces carry opposite charges, just like the plates of aparallel-plate capacitor. Suppose a typical cell membrane has athickness of 6.1×10^−9 m, and its inner and outer surfaces carrycharge densities of −7.7×10−4 C/m^2 and +7.7×10^−4 C/m^2,respectively. In addition, assume that the material in the cellmembrane has a dielectric constant of 3.1
(a) Find the direction of the electric field within the cellmembrane. a) into the cell b) out of the cell
(b) Find the magnitude of the electric field within the cellmembrane.
(c) Calculate the potential difference between the inner andouter walls of he membrane (Note: express answer inmillivolts,)
(d) Which wall has the higher potential a) inner wall b) outerwall  Â
Into the cell
Out of the cell
(b) Find the magnitude of the electric field within the cellmembrane.
E=E= Answer NCNC
(c) Calculate the potential difference between the inner andouter walls of the membrane. (NOTE: Express your answer inmillivolts, mV.)
ΔV=ΔV= Answer mVmV
(d) Indicate which wall of the membrane has the higherpotential.
Inner wall
Outer wall
