A model of a red blood cell depicts the cell as a spherical capacitor, a positively charged liquid sphere of surface area A separated from the surrounding negatively charged fluid via a membrane of thickness t. Tiny electrodes introduced into the interior of the cell represent a potential difference of 100 mV across the membrane. The membrane's thickness is anticipated to be 96 nm and consists of a dielectric constant of 5.00.
(i) When an average red blood cell consists of a mass of 1.1e-12 kg, approximate the volume of the cell and therefore determine its surface area. The density of blood is 1100 kg/m3. Volume = 1 m3
Surface area = 2 m2
(ii) Approximate the capacitance of the cell by supposing the membrane surfaces act as parallel plates.
(iii) Compute the charge on the surface of the membrane.