Before revision:  503 (1993) . In combination with reaction fluxes , they can be used to decorate the metabolic model with a yield flux network. The yield flux network shows a kind of gauge invariance with respect to rescaling of the stoichiometric matrix, and is arguably more fundamental than either the reaction fluxes or shadow prices. Complementary slackness implies that the yield flux network also satisfies a conservation law, which can be used to explain why the shadow prices are strongly correlated with measures of molecular complexity such as molecular weight and atom count.
After revision:  503 (1993) A metabolic model can be represented as bipartite graph comprising linked reaction and metabolite nodes. Here it is shown how a network of conserved fluxes can be assigned to the yield flux network also satisfies a conservation law, which can be used to explain why the shadow prices are strongly correlated with measures of molecular complexity such as molecular weight and atom count.