Systems Biology

<p>A <b>metabolic network</b> is the complete set of metabolic and physical processes that determine the <a href="http://en.wikipedia.org/wiki/Physiology" title="Physiology">physiological</a> and <a href="http://en.wikipedia.org/wiki/Biochemistry" title="Biochemistry">biochemical</a> properties of a <a href="http://en.wikipedia.org/wiki/Cell_%28biology%29" title="Cell (biology)">cell</a>. As such, these networks comprise the chemical reactions of <a href="http://en.wikipedia.org/wiki/Metabolism" title="Metabolism">metabolism</a>, the <a href="http://en.wikipedia.org/wiki/Metabolic_pathway" title="Metabolic pathway">metabolic pathways</a>, as well as the regulatory interactions that guide these reactions.

With the sequencing of complete <a href="http://en.wikipedia.org/wiki/Genomes" title="Genomes" class="mw-redirect">genomes</a>, it is now possible to reconstruct the network of biochemical reactions in many organisms, from bacteria to human. Several of these networks are available online: Kyoto Encyclopedia of Genes and Genomes (KEGG)<a rel="nofollow" class="external autonumber" href="http://www.genome.ad.jp">[1]</a>, EcoCyc <a rel="nofollow" class="external autonumber" href="http://www.ecocyc.org">[2]</a>, BioCyc <a rel="nofollow" class="external autonumber" href="http://biocyc.org">[3]</a> and metaTIGER <a rel="nofollow" class="external autonumber" href="http://www.bioinformatics.leeds.ac.uk/metatiger/">[4]</a>. Metabolic networks are powerful tools for studying and modelling metabolism.</p>