  We present a differential rate equation model of chiral polymerization based
on a simple copolymerization scheme in which the enantiomers are added to, or
removed from, the homochiral or heterochiral chains (reversible stepwise
isodesmic growth or dissociation). The model is set up for closed systems and
takes into account the corresponding thermodynamic constraints implied by the
reversible monomer attachments, while obeying a constant mass constraint. In
its simplest form, the model depends on a single variable rate constant, the
maximum chain length N, and the initial concentrations. We have fit the model
to the experimental data from the Rehovot group on lattice-controlled chiral
amplification of oligopeptides. We find in all the chemical systems employed
except for one, that the model fits the measured relative abundances of the
oligopetides with higher degrees of correlation than from a purely random
polymerization process.
