Assuming no change in either the internal or external calcium ion concentration, at what membrane potential would there be no net movement of calcium across the membrane?

Question

A cell biologist interested in the transport of calcium ions (Ca2+) across the plasma membrane of bacterial cells made the following measurements on bacterial cells at 25°C:

Vm = ?150 mV [Ca2+] outside = 20 mM [Ca2+] inside = 0.4 mM

A) ?25 mV
B) ?50 mV
C) 0 mV
D) +25 mV
E) +50 mV

Answer 1

Answer: B