Monte Carlo spreadsheet modeling of stable isotope biosynthesis

Abstract

Metabolic physiologists often introduce stable isotopes, atoms containing additional neutrons, into molecules during biosynthesis. This tags the newly synthesized material by altering its mass. Monte Carlo analysis is implemented on a popular spreadsheet to analyze this process. An example is provided where acetoacetate is synthesized by condensation of two acetate moieties. The precursor acetate is present as a mixture of natural, and 13C enriched, acetate. Monte Carlo spreadsheet modeling captures the complexity of the multi-species isotope biosynthesis by repetitively performing multiple simultaneous Boolean calculations. The effects of increasing the number of molecules synthesized on the goodness of fit of between model and an exact analytical solution is illustrated.