Early Mars was likely habitable, but could life actually have started there? While cellular life emerged from prebiotic chemistry through a pre-Darwinian selection process relevant to both Earth and Mars, […]
Life
Posted inAstrochemistry, Biochemistry & Organic Chemistry, Biophysics, Imaging & Spectroscopy, Interstellar, Status Report
The Mystery Of Homochirality On Earth
Homochirality is an obvious feature of life on Earth. On the other hand, extraterrestrial samples contain largely racemic compounds. The same is true for any common organic synthesis.
Posted inExtremeophiles and Extreme Environments, Mars, Microbiology & Virology, Planetary Protection & Biosafety, Status Report, Tardigrades
Long-Term Survivability of Tardigrade Paramacrobiotus experimentalis (Eutardigrada)at Increased Magnesium Perchlorate Levels: Implications for Astrobiological Research
Perchlorate salts, including magnesium perchlorate, are highly toxic compounds that occur on Mars at levels far surpassing those on Earth and pose a significant challenge to the survival of life […]
Posted inLife Support Systems, Mars, Microbiology & Virology, Plant Biology, Space Agriculture, Status Report
Cultivation of Chroococcidiopsis thermalis Using Available In Situ Resources to Sustain Life on Mars
The cultivation of cyanobacteria by exploiting available in situ resources represents a possible way to supply food and oxygen to astronauts during long-term crewed missions on Mars.
![Coupled evolutionary advances favoring emergence and fostering the specialization of genetic coding. (a). Interdependences involved in embedding specific recognition into the sequence space of folded proteins [26]. (b). Experimentally measurable metrics corresponding to (a). Although experimental models exist for each process, confirming details requires further work. -- LIFE](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/02/Base-Pairing.png?resize=1200%2C718&ssl=1)
Posted inBiochemistry & Organic Chemistry, Biophysics, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
Base Pairing Promoted the Self-Organization of Genetic Coding, Catalysis, and Free-Energy Transduction
How Nature discovered genetic coding is a largely ignored question, yet the answer is key to explaining the transition from biochemical building blocks to life. Other, related puzzles also fall […]
Posted inGenomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Status Report
The Key Steps in the Origin of Life to the Formation of the Eukaryotic Cell
The path from life’s origin to the emergence of the eukaryotic cell was long and complex, and as such it is rarely treated in one publication.
Posted inBiophysics, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
Evolution At The Origins Of Life?
The role of evolutionary theory at the origin of life is an extensively debated topic. The origin and early development of life is usually separated into a prebiotic phase and […]
![The proto-ribosome: (a) The symmetrical region within the 23S rRNA of E. coli ribosome (PDB code 2AW4). The A- and P-subregions, in blue and green, respectively, throughout. Helices H68-H71 were removed to reveal the PTC area. (b) 2D scheme of the symmetrical region (on colored background), drawn in a manner exhibiting the twofold symmetry, with the central loop of domain V (C-loop) at its center. The sequence assigned to the remnant of the DPR (boundary marked) is composed of two L-shaped molecules, the A- and P-DPR monomers. Nucleotides conserved by more than 97% in each of the three life domains, as detected in the CRW site [77], are presented by capital letters and the remaining nucleotides by circles. (c) Overlap of the DPR fold as found in the high-resolution structures of archaea (PDB code 1VQ6), bacteria (PDB code 2WDL), and eukarya (PDB code 3U5D) ribosomes, portraying its extreme tertiary conservation in the three life domains. The pocket is projected approximately along the symmetry axis, with the reactants (PDB code 2WDL) positioned at the bottom of the cavity. (d) Overlap of the A- and P-DPR monomers from E. coli (PDB code 2AW4), obtained by rotating one monomer by 179.6° around the symmetry axis. The projection direction is perpendicular to the one shown in (c). tRNA molecule (PDB code 4TRA, in gray) is overlaid with its anticodon arm overlapping H89 and H93 helices from the P- and A-monomers, respectively. Magnified nucleotides from the superimposed stems of H89 and its symmetry-related H93 depict the conformational match. Nucleotide A2602, which is functionally active, bulges into the PTC and breaks the overall symmetry. (e) Model of a minimal coded proto-ribosome assembled from four L-shaped entities of about 60–70 nucleotides each (derived from PDB code 1VY4), i.e., the A-, P-DPR monomers, the proto-SSU (purple), and the bridging element (dark red), complexed with mRNA (orange) and tRNA (cyan). -- LIFE](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/02/Three-Biopolymers.png?resize=1200%2C716&ssl=1)
Posted inBiochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
Three Biopolymers And Origin Of Life Scenarios
To track down the possible roots of life, various models for the initial living system composed of different combinations of the three extant biopolymers, RNA, DNA, and proteins, are presented.
Posted inAstrochemistry, Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, TRAPPIST-1
The Effect Of Lightning On The Atmospheric Chemistry Of Exoplanets And Potential Biosignatures
Lightning has been suggested to play a role in triggering the occurrence of bio-ready chemical species. Future missions (PLATO, ARIEL, HWO, LIFE) and ground-based ELTs will investigate the atmospheres of […]
Posted inBiochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
From the RNA-Peptide World: Prebiotic Reaction Conditions Compatible with Lipid Membranes for the Formation of Lipophilic Random Peptides in the Presence of Short Oligonucleotides, and More
Deciphering the origins of life on a molecular level includes unravelling the numerous interactions that could occur between the most important biomolecules being the lipids, peptides and nucleotides. They were […]