Movie 5. Probability [Low affinity] = 0.1   The simulation of Movie 4 is repeated, but now for 200,000 steps with only every 200th frame being displayed. Each blue square in the bottom compartment indicates that 100 ions have crossed. During this simulation 240 K and 26 Na ions have permeated, making the K/Na flux ratio close to 10. If this simulation is repeated many times, the mean ratio is statistically indistinguishable from 10: a probability of being in the low-affinity state of 0.1 results in a K/Na flux ratio of 10.    (Movie 6)     (Back)