FIGURE 1 

(A) Changes in the concentration of key metabolites in response to overall decreases in the V_max values for the reactions of glycolysis (blue, left axis scale), as well as the change in PYK flux over the same range (red, right axis scale). (B) Ratio of the flux through pyruvate decarboxylase (PDC, fermentative pathways) to the flux through pyruvate dehydrogenase (PDH, respiratory pathway) as a function of pyruvate concentration and the ratio of NAD⁺ to NADH concentration (because NAD⁺ and NADH are two oxidation states of the same molecule, their concentrations vary inversely and hence are constrained to sum to 8.01 in B; Theobald et al, 1997). (C) Effect of compartmentalization on the relative fluxes of the first reaction in respiration (PDH) and in fermentation (PDC). On the x-axis is the relative enzyme concentration modeling a change from a rough pre-duplication state of 0.65 to a post-duplicate value of 1.0 (see A). On the y-axis is given the ratio of the fluxes between the two reactions relative to the flux when [E] on the x-axis is equal to 1.0.