BIO304H5 Study Guide - Midterm Guide: Nernst Equation, Goldman Equation, Voltage Source
Document Summary
The more dilute the electrolyte soln, the higher the resistance, the lower its conductivity. Fewer ions available to carry the current: the cross sectional area of the soln (in a plane perpendicular to the direction of current flow) The small the cross sectional area, the higher the resistance encountered by the current. Analogous to the pipe: the distance traversed in soln by the current. The difference in the conc favors the movement of k+ from compartment i. Chemical gradient favoring a net flux of k+ from i to ii. Electric potential difference favoring a net flux of k+ from ii to i: after some time, the opposing forces come into equilibrium and remain balanced. The electromotive force (emf) due to the electric potential difference across the membrane precisely counteracts (offsets) the tendency for k+ to diffuse down its conc gradient. At this point, k+ is in electrochemical equilibrium.
