Some generic measures of the extent of chemical disequilibrium applied to living and abiotic systems.

Abstract

We report results of evaluation of several measures of chemical disequilibrium in living and abiotic systems. The previously defined measures include R_{T} and R_{L}, which are Euclidean distances of a coarse grained polymer length distribution from two different chemical equilibrium states associated with equilibration to an external temperature bath and with isolated equilibration to a distribution determined by the bond energy of the system, respectively. The determination uses a simplified description of the energetics of the constituent molecules. We evaluated the measures for data from the ribosome of E. coli, a variety of yeast, and the proteomes (with certain assumptions) of a large family of prokaryotes, and for mass spectrometric data from the atmosphere of the Saturn satellite Titan and for nonliving commercial copolymers. We find with surprising consistency that R_{L} is much smaller than R_{T} for all these systems. The living (protein) systems have a well defined value of R_{T} that is sharply defined and distinct from that obtained from the nonliving Titan and copolymer systems. The living systems are also distinguishably characterized by larger values of R_{L} than most of the nonliving systems, but R_{L} values vary more from one living system to another than the R_{T} values do. These data suggest that the measures R_{L} and R_{T} can distinguish living from nonliving systems.