The transition from the RNA world to cellular life remains one of the least understood events in the history of biology.
Tag: RNA world
Posted inAstrochemistry, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Genomics, Proteomics, Bioinformatics, Habitable Zones, Impact events, Meteorites & Asteroids, Origin & Evolution of Life
Atmospheric Supply Of HCN Is Not The Rate Limiting Step For Prebiotic Chemistry Across Rocky Exoplanets
![Kinetic processes of the strand-based RNA reactor model [12,13,15] and their projection onto motif kinetics. We consider heteropolymer strands consisting of the two complementary nucleotides X and Y, which could represent RNA or DNA nucleotides. (a) Schematic of the reactions within the strand reactor, including hybridization, dehybridization, templated ligation, and cleavage of oligonucleotide strands. Strands that are not covalently linked are separated by small gaps; four-nucleotide motifs, including 3′ or 5′ ends, are highlighted in green. In templated ligation, a 3′- and a 5′-end motif build a six-nucleotide motif that contains three overlapping four-nucleotide motifs. (b) At the level of sequence motifs, the kinetics are based on motif production and motif breakage reactions. In four-nucleotide motifs, strand ends are marked with 3′ or 5′, respectively. Templated ligation generates longer strands containing additional motifs, thereby contributing to motif production, while strand cleavage leads to to motif breakage. Hybridization is not explicitly represented in the motif-level description; instead, it is implicitly incorporated into the rate constants for motif production and breakage by assuming a hybridization-dehybridization equilibrium and deducing the corresponding dissociation constants. -- Physical Review E](https://astrobiology.newspackstaging.com/wp-content/uploads/2026/03/Sequence-Motif-Dynamics.png)
![Scheme of a geothermal valley between two snow-covered Hadean volcanoes. The fumaroles, thermal springs, apron pools, and terracettes are shown based on the reconstruction of the 3.48 Ga old Hadean geothermal system. On the right, various reactions of CO2 sequestration in a Hadean volcanic system are indicated, see Section 3.2.5 and Section 3.2.6. Inserts: (A) volcanic fumaroles, image from https://home.nps.gov/articles/000/fumaroles.htm, credit: USGS. (B) Schematic cross section of a pH-neutral hot spring, redrawn with modifications from [341,342]. (C) White Terraces of New Zealand as an example of volcanic terracettes (painted by Charles Bloomfield in 1884, two years before the terraces were buried under the waters of the lake Rotomahana following the eruption of Mt. Tarawera. Image credit: Museum of New Zeeland, https://collections.tepapa.govt.nz/object/42254, accessed on 23 December 2024.). (D) Interconversion of nitriles, amides, and ammonium salts of organic acids, represented by their simplest species, in geothermal pools in the presence of inorganic catalysts; each of the nitrogen-containing compounds shown is considered as a substrate for further synthetic reactions. Formamide and other amides, as the least volatile components, may have sustained/buffered the whole system. -- Life via PubMed](https://astrobiology.newspackstaging.com/wp-content/uploads/2025/07/Origin-Of-The-RNA-World-In.png)
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