Biochemical Phenomena Constraint-based modeling Constraint-based models Constraints-based modeling E-Flux E-flux Enzyme activity Escherichia coli Gene expression Gene expression integration Genes expression Metabolic Networks and Pathways Metabolic flux distribution Metabolic reconstruction Metabolism Models, Biological Proportionality constant Saccharomyces cerevisiae Transcript level Transcriptome Transcriptomics Yeast algorithm article biochemistry biological model extraction genetics metabolism nonhuman