  We investigate the propagation of random fluctuations through biochemical
networks in which the concentrations of species are large enough so that the
unperturbed problem is well-described by ordinary differential equation. We
characterize the behavior of variance as fluctuations propagate down chains,
study the effect of side chains and feedback loops, and investigate the
asymptotic behavior as one rate constant gets large. We also describe how the
ideas can be applied to the study of methionine metabolism.
