Chapter 26, Problem 64MSPP

Cell Membrane Resistance

The capacitance of biological membranes is about 1.0 μF per cm² of membrane area, so investigators can determine the surface area of a cell membrane by using intracellular electrodes to measure the membrane’s capacitive reactance. An investigator applies a 1.0 μA peak current at 40 kHz to a cell and measures the peak out-of-phase voltage—that is, the component of the voltage due to the capacitive reactance of the cell membrane—to be 0.16 V.

If the capacitance of a cell membrane is measured to be 6.0 × 10^–11 F, what is the area?

A. 6.0 × 10^–13 m²

B. 6.0 × 10^–11 m²

C. 6.0 × 10^–9 m²

D. 6.0 × 10^–7 m²