Skip to main content
. 2009 Jan 20;7(1):e21. doi: 10.1371/journal.pbio.1000021

Figure 1. Example of a Dynamical System.

Figure 1

(A) Reaction schematic of an enzyme, E, catalyzing the conversion of substrate, S, to product, P. The final product acts as a catabolite to promote the expression of enzyme.

(B) ODE describing the change in time of enzyme concentration, c. The first term is the production term, r p(c), and the second term is degradation, r d(c).

(C) Graphical representation of r p(c) and r d(c). At steady state, these two processes will balance, and the concentration of enzyme will become constant in time, with a value corresponding to the intersection of these two curves. Increasing the degradation constant μ (depicted by shift from solid line to dashed line) changes the steady state value of c (from closed circle to open circle). The sensitivity of this steady state value of c to such changes in parameters can be quantified by the sensitivity coefficient.