A model of a red blood cell portrays the cell as a sphericalcapacitor, a positively charged liquid sphere of surface area Aseparated from the surrounding negatively charged fluid by amembrane of thickness t. Tiny electrodes introduced into theinterior of the cell show a potential difference of 100 mV acrossthe membrane. The membrane's thickness is estimated to be 96 nm andhas a dielectric constant of 5.00.
(a) If an average red blood cell has a mass of 1.1e-12 kg, estimatethe volume of the cell and thus find its surface area. The densityof blood is 1100 kg/m3. volume = 1 m3
surface area = 2 m2
(b) Estimate the capacitance of the cell by assuming the membranesurfaces act as parallel plates.
3 F
(c) Calculate the charge on the surface of the membrane.
4 C
How many electronic (elementary) charges does the surface chargerepresent?
5
A model of a red blood cell portrays the cell as a sphericalcapacitor, a positively charged liquid sphere of surface area Aseparated from the surrounding negatively charged fluid by amembrane of thickness t. Tiny electrodes introduced into theinterior of the cell show a potential difference of 100 mV acrossthe membrane. The membrane's thickness is estimated to be 96 nm andhas a dielectric constant of 5.00.
(a) If an average red blood cell has a mass of 1.1e-12 kg, estimatethe volume of the cell and thus find its surface area. The densityof blood is 1100 kg/m3. volume = 1 m3
surface area = 2 m2
(b) Estimate the capacitance of the cell by assuming the membranesurfaces act as parallel plates.
3 F
(c) Calculate the charge on the surface of the membrane.
4 C
How many electronic (elementary) charges does the surface chargerepresent?
5
