  We consider biochemical reaction chains and investigate how random external
fluctuations, as characterized by variance and coefficient of variation,
propagate down the chains. We perform such a study under the assumption that
the number of molecules is high enough so that the behavior of the
concentrations of the system is well approximated by differential equations. We
conclude that the variances and coefficients of variation of the fluxes will
decrease as one moves down the chain and, through an example, show that there
is no corresponding result for the variances of the chemical species. We also
prove that the fluctuations of the fluxes as characterized by their time
averages decrease down reaction chains. The results presented give insight into
how biochemical reaction systems are buffered against external perturbations
solely by their underlying graphical structure and point out the benefits of
studying the out-of-equilibrium dynamics of systems.
