Exact results for noise power spectra in linear biochemical reaction   networks
  We present a simple method for determining the exact noise power spectra in linear chemical reaction networks. We apply the method to networks which are representative of biochemical processes such as gene expression and signal detection. Our results clarify how noise is transmitted by signal detection motifs, and indicate how to coarse-grain networks by the elimination of fast reactions. 
Patrick B. Warren, Sorin Tanase-Nicola, Pieter Rein ten Wolde