Graphs from the prebranch, the postbranch, and the signalling cascade model. The first two models contain only reversible Michaelis Menten kinetics with most parameters (V
(maximum backward velocity), K
(binding constant of the substrate), K
(binding constant of the product)) set to 1 and all V
(maximum forward velocity) values set to 10. The concentrations of the topmost substances in these models (species_1 and in the prebranch species_4) are set to 1 and kept fixed and the concentrations of the bottommost ones are kept at 0. In both cases the steady state concentration of species_7 is to be minimized. In the third model the concentrations of the activated receptor (Ra) and the inactive kinases (X, Y, and Z) are set to 1 while all others are set to 0. The phosphorylation steps (reactions 2, 4, and 6) occur at a rate of , the dephosphorylation steps (reactions 3, 5, and 7) at , and the receptor inactivation (reaction 1) at v = 0.1 * Ra. This figure has been produced with the help of sbml2dot .