Demonstration results of the described procedure in Figure 1. A) The unimodal and bimodal reaction sets whose flux states essentially dictate the flux state of the entire metabolic network in glucose aerobic conditions. The reaction sets are colored to distinguish modality (blue and red for bimodal, blue for unimodal.) Extracellular metabolites are denoted with an appended '(e)'. See Additional file 4 for full metabolite and reaction names. B) The two randomly generated network flux distributions that most oppositely utilized the first reaction set in A), where the β values from Equation 1 are colored according to the accompanying color spectrum key.