Figure 2

The binary form of the metabolite coupling matrix for E. coli. The binary form of M for E. coli is shown. Approximately 98% of the values in M are zero, so 98% of the image is white. Off-diagonal black points only appear where two metabolites occur in at least one reaction together. The diagonal and the prominence of coupling in the first few rows and columns (most connected metabolites) is clearly illustrated. As in figure 2, each row and column represents a particular metabolite.