Many cells in the body have a cell membrane whose inner and outer surfaces carry

Question

Many cells in the body have a cell membrane whose inner and outer surfaces carry opposite charges, just like the plates of a parallel-plate capacitor. Suppose a typical cell membrane has a thickness of 8.5×109 m , and its inner and outer surfaces carry charge densities of -6.3×104 C/m2 and +6.3×104 C/m2 , respectively. In addition, assume that the material in the cell membrane has a dielectric constant of 5.5. A. Calculate the potential difference between the inner and outer walls of the membrane.

Explanation / Answer

surface charge density, sigma = 6.3 x 10^-4 C/m^2

d = 8.5 x 10^-9 m

Field inside the membrane, E = sigma / e0 er

E = (6.3 x 10^-4) / (5.5 x 8.854 x 10^-12)

E = 12.9 x 10^6 N/C

Potential diff = E.d

= (8.5 x 10^-9)(12.9 x 10^6)

= 0.11 Volt ......ANs

Related Questions

Navigate

• Browse (All)
• Browse M
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.