 Keeping all terms except "V"m constant, the equation yields a straight line when plotting "formula_2"S against "V"m. It is evident that the ratio between the two asymptotes is merely the ratio between the two concentrations of S, [S]i and [S]o.Thus, if the two concentrations are identical, the slope will be identical (and constant) throughout the voltage range (corresponding to Ohm's law scaled by the surface area).As the ratio between the two concentrations increases, so does the difference between the two slopes, meaning that the current is larger in one direction than the other, given an equal driving force of opposite signs.