Fig. 2

ModelExplorer graphical features: a The search tool in the command panel can be used to search for reactions and species by their id or name. If one selects the desired item from a drop-down list of matches, a purple circle is drawn around the target, and a line of similar colour is drawn from the lower left corner of the network view to the circle. b In node ancestry mode, one can view the shortest pathway (all the way to import reactions) necessary to produce a species or to make a reaction active. It gets highlighted in dark purple colour if non-cyclic. If cyclic, the cycle (strongly connected component) gets highlighted in black