Figure 1

Animal cells metabolic network [2, 7] From the reactions of table 1, it was further assumed that r_e6=r_e7 since DNA and RNA are made up of equal parts of purine and pyrimidine. Therefore, these two reactions were substituted by their sum:

2Glc+5 Gln→Pur+Pyr+4CO₂+2Amm

Furthermore, it was considered that the 4th elementary mode has negligible flux, since lactate is mainly produced from glucose.