  While atom tracking with isotope-labeled compounds is an essential and
sophisticated wet-lab tool in order to, e.g., illuminate reaction mechanisms,
there exists only a limited amount of formal methods to approach the problem.
Specifically when large (bio-)chemical networks are considered where reactions
are stereo-specific, rigorous techniques are inevitable. We present an approach
using the right Cayley graph of a monoid in order to track atoms concurrently
through sequences of reactions and predict their potential location in product
molecules. This can not only be used to systematically build hypothesis or
reject reaction mechanisms (we will use the ANRORC mechanism "Addition of the
Nucleophile, Ring Opening, and Ring Closure" as an example), but also to infer
naturally occurring subsystems of (bio-)chemical systems. Our results include
the analysis of the carbon traces within the TCA cycle and infer subsystems
based on projections of the right Cayley graph onto a set of relevant atoms.
