The Effect of Limited Diffusion and Wet–Dry Cycling on Reversible Polymerization Reactions: Implications for Prebiotic Synthesis of Nucleic Acids

摘要: A long-standing problem for the origins of life is that polymerization many biopolymers, including nucleic acids and peptides, thermodynamically unfavourable in aqueous solution. If bond making breaking reversible, monomers very short oligomers predominate. Recent experiments have shown wetting drying cycles can overcome this drive formation longer polymers. In dry phase, favourable, but diffusion restricted, bonds only form between are initially close together. wet some hydrolyzed. However, repositioning molecules allows new to next leading an increase mean polymer length. Here, we consider a simple theoretical model explains effect cycling. There equilibrium length distribution with high could be achieved if occurred freely phase. This inaccessible without diffusion. single cycle leads lengths much shorter than this. Repeated cycling significant relative cycle. most favourable case, same as would free were possible These results support RNA World scenario by explaining potential route synthesis long RNAs; however, they also imply beneficial other kinds polymers, where involves condensation reaction.