Figure 1
The pathway of galactose metabolism [20]. Substances (X1–5) represent the following metabolites in the paper referenced: X1, external galactose (GAE); X2, internal galactose (GAI); X3, galactose 1-phosphate (G1P); X4, UDP-glucose (UGL); and X5, UDP-galactose (UGA). The reactions are VTR, transporter of galactose; VGK, catalyzed by galactokinase; VGT, catalyzed by galactose-1-phosphate uridyltransferase; VEP, catalyzed by UDP-galactose 4-epimerase. X3 is an inhibitor whose rate is given as VGK. The kinetic equations, systems parameters, and initial conditions of this model are shown in Appendix 1.