beecee Posted October 20, 2021 Share Posted October 20, 2021 https://phys.org/news/2021-10-team-approach-unveil-life-evaporation.html Team discovers a new approach to unveil the Origin of Life: Evaporation: The image shows the evaporation-induced phase separation process inside an all-aqueous sessile droplet (Scale bar: 500 microns). The droplet is initially single-phase with PEG (Polyethylene glycol) and dextran dissolved. Upon evaporation, the concentration of PEG and dextran increases and incompatibility arises, forming tiny dextran-rich droplets (green fluorescently labelled) dispersed in the continuous PEG-rich phase. These tiny dextran-rich droplets move towards the center of the sessile droplet with the inward Marangoni flow. Compartmentalization and localization of biopolymers like nucleic acids (red fluorescently labelled) inside these dextran-rich droplets are achieved, with great potential in serving as all-aqueous reactors for a wide range of biochemical reactions. Credit: The University of Hong Kong What is the origin of life? It is a question that has consumed the work and time of scientists for centuries. Recently a group of researchers from the University of Hong Kong (HKU) has shed light on the possible ways forward to examine how living things are formed. more at link.... the paper: https://www.nature.com/articles/s41467-021-23410-7 Non-associative phase separation in an evaporating droplet as a model for prebiotic compartmentalization: Abstract: The synthetic pathways of life’s building blocks are envisaged to be through a series of complex prebiotic reactions and processes. However, the strategy to compartmentalize and concentrate biopolymers under prebiotic conditions remains elusive. Liquid-liquid phase separation is a mechanism by which membraneless organelles form inside cells, and has been hypothesized as a potential mechanism for prebiotic compartmentalization. Associative phase separation of oppositely charged species has been shown to partition RNA, but the strongly negative charge exhibited by RNA suggests that RNA-polycation interactions could inhibit RNA folding and its functioning inside the coacervates. Here, we present a prebiotically plausible pathway for non-associative phase separation within an evaporating all-aqueous sessile droplet. We quantitatively investigate the kinetic pathway of phase separation triggered by the non-uniform evaporation rate, together with the Marangoni flow-driven hydrodynamics inside the sessile droplet. With the ability to undergo liquid-liquid phase separation, the drying droplets provide a robust mechanism for formation of prebiotic membraneless compartments, as demonstrated by localization and storage of nucleic acids, in vitro transcription, as well as a three-fold enhancement of ribozyme activity. The compartmentalization mechanism illustrated in this model system is feasible on wet organophilic silica-rich surfaces during early molecular evolution. Link to comment Share on other sites More sharing options...
jimmydasaint Posted October 23, 2021 Share Posted October 23, 2021 Good find beecee. This article seems to be crossing the abiogenesis -biogenesis divide. Just a couple of questions. 1. Which organelles form this way in a cell which is approximately 90 percent water? 2. Presumably these experiments use pure reactants. Have they extended a similar model towards a "noisy" cell environment? I don't have time to read the whole article but presume you have mate. Cheers Link to comment Share on other sites More sharing options...
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