Figure 8.
The effect of altered O2 concentration on metabolic fluxes. A, Standard O2; B, Elevated O2. The width of arrows is proportional to flux of carbon through a particular step calculated from the flux estimates in Table II and the number of carbon atoms in the metabolites involved in each reaction. Reactions that carry no flux under the specified condition are not included. Forward and reverse fluxes for ana1 (PEPCK) are illustrated. Exchange fluxes for tca4 and tca5a + 5b were also determined (Table II) but are omitted for clarity. The fraction of carbon entering the TCA cycle used for biosynthesis was calculated as: (4ana3 + 4asp + 5glu + 6scit + 4smal + 4ssucc + 4sfumOUT)/(3cmex + 4ana1).