Origin of self-replicating biopolymers: autocatalytic feedback can jump-start the RNA world.

摘要: Life is based on biopolymers that have the ability to replicate themselves. Here we consider how a self-replicating RNA system may originated. We reaction in which polymerization possible by addition of an activated monomer end chain. suppose small fraction polymers longer than some minimum length L act as polymerase ribozymes. Polymerization can occur spontaneously at slow rate and also be catalyzed ribozymes, if these ribozymes exist. The contains autocatalytic feedback: increasing causes ribozyme concentration increase, further increase. For infinite volume, dynamics are deterministic. There two stable states: ‘dead’ state with very low almost equal spontaneous rate, ‘living’ high occurring via catalysis. In finite such interior lipid vesicle or other compartment, stochastic fluctuations occur. Using simulation, show number initially formed spontaneously, this enough drive from dead living where ribozyme-catalyzed synthesis large numbers additional occurs. This transition occurs most easily volumes intermediate size.