2011/12/31 by Marcelo Gleiser, Bradley J. Nelson, Sara Imari Walker
Biochemistry, Genetics and Molecular Biology · Chemistry · Earth and Planetary Sciences · Physics and Astronomy · #Autocatalysis #Chemistry and Stereochemistry Studies #Chirality (physics) #Enantiomer #Enantiomeric excess #Homochirality #Origins and Evolution of Life #Paleontology and Stratigraphy of Fossils #Polymerization #Reaction calorimeter #Reaction rate #q-bio.BM
paper · pdf · doi:10.1007/s11084-012-9274-5
15 pages, 6 figures, accepted for publication in Origins of Life and Evolution of Biospheres
arxiv created 2012/04/26 · openalex publication_date 2012/05/18 · arxiv updated 2015/06/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We investigate the possibility that prebiotic homochirality can be achieved exclusively through chiral-selective reaction rate parameters without any other explicit mechanism for chiral bias. Specifically, we examine an open network of polymerization reactions, where the reaction rates can have chiral-selective values. The reactions are neither autocatalytic nor do they contain explicit enantiomeric cross-inhibition terms. We are thus investigating how rare a set of chiral-selective reaction rates needs to be in order to generate a reasonable amount of chiral bias. We quantify our results adopting a statistical approach: varying both the mean value and the rms dispersion of the relevant reaction rates, we show that moderate to high levels of chiral excess can be achieved with fairly small chiral bias, below 10%. Considering the various unknowns related to prebiotic chemical networks in early Earth and the dependence of reaction rates to environmental properties such as temperature and pressure variations, we argue that homochirality could have been achieved from moderate amounts of chiral selectivity in the reaction rates.