Question

You find a novel organism with unique structure and begin to study its nervous system. You find that Vm = -40 mV. Important

ions in this system appear to be magnesium(Mg^2+) and Rubidium (Rb^+)

Ion: Rb^+
Intracellular Concentration (mM): 200
Extracellular Concentration (mM): 5

Ion: Mg^2+

Intracellular Concentration (mM): 50
Extracellular Concentration (mM): 400

For this system, the concentration gradient for magnesium favors [×] and the electrical gradient favors [y].

A) efflux; efflux
B) influx; efflux
C) influx; no effect
D) influx; influx
(E) efflux; influx

Answer 1

I think the answer is B. Influx; efflux.
The Magnesium is moving from low concentration to high concentration, which supports influx. The electrical gradient is moving from high concentration to low concentration, which favors efflux.