  Starting from our recent chemical master equation derivation of the model of
an autocatalytic reaction-diffusion chemical system with reactions $U+2V
{\stackrel {\lambda_0}{\rightarrow}}~ 3 V;$ and $V {\stackrel
{\mu}{\rightarrow}}~P$, $U {\stackrel {\nu}{\rightarrow}}~ Q$, we determine the
effects of intrinsic noise on the momentum-space behavior of its kinetic
parameters and chemical concentrations. We demonstrate that the intrinsic noise
induces $n \rightarrow n$ molecular interaction processes with $n \geq 4$,
where $n$ is the number of molecules participating of type $U$ or $V$. The
momentum dependences of the reaction rates are driven by the fact that the
autocatalytic reaction (inelastic scattering) is renormalized through the
existence of an arbitrary number of intermediate elastic scatterings, which can
also be interpreted as the creation and subsequent decay of a three body
composite state $\sigma = \phi_u \phi_v^2$, where $\phi_i$ corresponds to the
fields representing the densities of $U$ and $V$. Finally, we discuss the
difference between representing $\sigma$ as a composite or an elementary
particle (molecule) with its own kinetic parameters. In one dimension we find
that while they show markedly different behavior in the short spatio-temporal
scale, high momentum (UV) limit, they are formally equivalent in the large
spatio-temporal scale, low momentum (IR) regime. On the other hand in two
dimensions and greater, due to the effects of fluctuations, there is no way to
experimentally distinguish between a fundamental and composite $\sigma$. Thus
in this regime $\sigma$ behave as an entity unto itself suggesting that it can
be effectively treated as an independent chemical species.
