Suppose that the constant of proportionality governing the rate at which chemical enters the cell is three times as large as the constant governing the rate at which it leaves. Would the concentration inside the cell be increasing or decreasing if C = Г? What would this mean for the cell?
The derivation of the movement of chemical assumed that chemical moved as easily into the cell as out of it. If the membrane can act as a filter, the rates at which chemical enters and leaves might differ, or might depend on the concentration itself. In each of the following cases, draw a diagram illustrating the situation and write the associated differential equation. Let C be the concentration inside the cell, r the concentration outside, and β the constant of proportionality relating the concentration and the rate.