0045-0005 Cascante.indd

Systems biology is based on the understanding that the behaviour of the whole is greater than would be expected from the sum of its parts. Thus the ultimate goal of systems biology is to predict the behaviour of the whole system on the basis of the list of components involved. Recent advances in ‘-omics’ technologies and the development of new computational techniques and algorithms have greatly contributed to progress in this fi eld of biology. Among the main ‘-omics’ technologies, metabolomics is expected to play a signifi cant role in bridging the phenotype–genotype gap, since it amplifi es changes in the proteome and provides a better representation of the phenotype of an organism than other methods. However, knowledge of the complete set of metabolites is not enough to predict the phenotype, especially for higher cells in which the distinct metabolic processes involved in their production and degradation are fi nely regulated and interconnected. In these cases, quantitative knowledge of intracellular fl uxes is required for a comprehensive characterization of metabolic networks and their functional operation. These intracellular fl uxes cannot be detected directly, but can be estimated through interpretation of stable isotope patterns in metabolites. Moreover, analysis of these fl uxes by means of metabolic control theories 1To whom correspondence should be addressed (email [email protected]). © The Authors Journal compilation © 2008 Biochemical Society