Figure 1From: A U-system approach for predicting metabolic behaviors and responses based on an alleged metabolic reaction networkExamples for typical metabolic pathways and U-system approach. a Simple linear pathway. A, B, and C represent metabolites. b Diagram for constructing a mathematical model using U-system approach. c Branched pathway with inhibition (⊕) and activation (⊖). X i (i=1, 2, 3 and 4) represent metabolites.Back to article page