Dynamics of the average level of protein <i>C</i> (red), level of protein <i>C</i> at the front (green) and back (blue) for noise in the external chemoattractant gradient (top) and internal signaling pathway (bottom).

<p>Dotted lines are the average level of protein in the absence of any noise. Values used are <i>β</i> = 1.0, , and <i>η</i> = 1.0 (top) and <i>ν</i> = 0.25 (below).