organic chemistry Archives

Unravel Life’s Cosmic Beginnings -- UH Manoa

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Habitable Zones, Interstellar, Press Release

UH Mānoa Scientists Help Unravel Life’s Cosmic Beginnings

by Keith CowingMay 15, 2024May 15, 2024

Knowledge about the early forms of life in the universe that may have led to the development of life on Earth remains largely unknown. However, a group of scientists at […]

Schematic (not to scale) showing the proposed origin of emission of the S-bearing species towards the CMZ of NGC 253 (Sec. 6.3) and summarising the main results for the physical properties (Tgas, ngas) of the gas emitting the S-bearing species (Sec 5.2). We illustrate two scenarios, for a giant molecular cloud in the outer (left) CMZ and inner (right) CMZ. The timescale for the shocks induced by star-formation are from Huang et al. (2023). The temperatures and densities reported are averaged over the regions and variations could be present in some of the regions. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Status Report

An ALCHEMI Inspection of Sulphur-bearing Species Towards the Central Molecular Zone of NGC 253

by Keith CowingMay 15, 2024May 15, 2024

Sulphur-bearing species are detected in various environments within Galactic star-forming regions and are particularly abundant in the gas phase of outflows and shocks, and photo-dissociation regions.

Difference IR spectra obtained after UV irradiation of C2H2:NH3 ice mixtures with ratios of (a) 1:0, (b) 1:0.2, (c) 1:0.5, (d) 1:1.4, and (e) 1:2.7 at 10 K for a fluence of 5.7×1017 photon cm−2 . Infrared spectra are offset for clarity. The shaded area marks the absorption features of the parent species (i.e., blue is for C2H2 and red is for NH3) now visible as negative bands. -- astro-ph.GA

Astrochemistry, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Status Report

Formation of N-bearing Complex Organic Molecules in Molecular Clouds: Ketenimine, Acetonitrile, Acetaldimine, and Vinylamine via the UV Photolysis of C2H2 Ice

by Keith CowingMay 14, 2024May 14, 2024

The solid-state C2H2 chemistry in interstellar H2O-rich ice has been proposed to explain astronomically observed complex organic molecules (COMs), including ketene (CH2CO), acetaldehyde (CH3CHO), and ethanol (CH3CH2OH), toward early star-forming […]

A plume of gas and ice grains emanates from the South Polar Terrain on Enceladus. The plume source is a global ocean of liquid water beneath the moon's icy crust. Plume materials erupt as diffuse “curtains” of water vapor punctured by ∼100 localized “jets” of gas and ice grains primarily 0.1–10 μm in size (Porco et al., 2006; Spitale et al., 2015). Small ice grains escape Enceladus' gravity and populate Saturn's E-ring, but larger, slower grains are ejected to an altitude of 30–50 km and then fall back (Goldstein et al., 2018). Image Credit: NASA/JPL-Caltech/Space Science Institute.

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Enceladus, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Enceladus: Astrobiology Revisited

by Keith CowingMay 14, 2024May 14, 2024

Astrobiology research seeks to understand how life begins and evolves, and to determine whether life exist elsewhere in the universe. The discovery of diverse ocean worlds has significantly expanded the […]

Preferential dissociation of 12CO2 against 13CO2 is expected in a wavelength region from 170 nm to 200 nm, which is responsible for solar UV photolysis of CO2. a, Actinic UV spectra. Red: solar spectrum from ref. 43. Blue: calculated spectrum at 30 km altitude (alt.) of model early Mars (10 mbar CO2 at surface) (Methods). Black: measured UV spectrum of the high pressure Xe lamp used in the laboratory experiment (Methods). b, Calculated absorption cross sections of 12CO2 (black) and 13CO2 (orange) at 295 K from ref. 17. c, Calculated isotope effect (1,000 ln α1) as a function of wavelength for the 295 K absorption spectra. Results were averaged over a 1 nm (black) and 5 nm (red) windows. Oxygen isotopic fractionation and its implications for Mars atmosphere were given elsewhere. -- CREDIT Tokyo Tech

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Fossils & Paleontology, Habitable Zones, Mars, Press Release

Tracing The Origins of Organic Matter in Martian Sediments

by Keith CowingMay 14, 2024

Although Mars presents a barren, dusty landscape with no signs of life so far, its geological features such as deltas, lakebeds, and river valleys strongly suggest a past where water […]

An artist's impression of this research. (Credit: NAOJ)

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Imaging & Spectroscopy, Press Release

A New Theory To Explain The Origin Of Phosphorus

by Keith CowingMay 12, 2024May 12, 2024

Astronomers have proposed a new theory to explain the origin of phosphorus, one of the elements important for life on Earth. The theory suggests a type of stellar explosion known […]

A phase-contrast micrograph of a ciliate (Frontonia sp.) digesting blue-green algae (cyanobacteria). The cytostome (the "mouth" of the cell) is seen on the right side down. Image credit: (CC BY-SA 4.0 DEED)

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life

Early Replicators

by Keith CowingMay 12, 2024May 12, 2024

Mathematical models of how ribonucleic acid (RNA)-like molecules make copies of themselves reveal new insights as the origins of life on Earth.

Hexose sugar permeability through archaeal and hybrid membranes. Temporal dependence of average carboxyfluorescein (CF) fluorescence in the archaea-like G1PC phospholipid membrane (G1PC, filled symbols) and in the ‘hybrid’ phospholipid membrane (G3PC, open symbols) during the exposure to 1 mM of variant substrates delivered to the microfluidic coves. Mean (symbols) and standard deviation (error bars) were calculated from at least 10 single-vesicle measurements across three independent experiments. Data are processed and illustrated as described in Figure 1 legend. N is the number of single vesicles investigated for each substrate exposure and each type of vesicles. **: p-value < 0.01. Numerical values of CF fluorescence in individual vesicles for each lipid type during the delivery of each substrate are provided in S1 File and S2 File. -- biorxiv.org

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report

Membrane Permeability Selection Drove the Stereochemistry of Life

by Keith CowingMay 9, 2024September 18, 2025

Early in the evolution of life a proto-metabolic network was encapsulated within a membrane compartment. The permeability characteristics of the membrane determined several key functions of this network by determining […]

(A) Schematic of assumptions concerning the outer layers of Enceladus, where H2 (and other solutes) and H2O erupt from the subsurface ocean as a plume of gas. As solutes and H2O vaporize and travel through the tiger stripes, H2O condenses onto the surrounding ice shell as it travels outward, enriching the plume in solutes. Once out of the ice shell conduit, the ratio of solutes to H2O remains the same as the gases expand into the vacuum of space and are detected by Cassini’s INMS. (B) Calculated log aqueous activities (at 273.15 K) of constrained species, resulting from the process illustrated in the left panel using data from Table 1, are displayed as functions of tiger-stripe temperatures. The dashed curve represents a hypothetical organic molecule detected at 1 ppm in the plume gas and then converted into log aqueous activity. -- chemrxiv.org

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, SETI & Technosignatures, Status Report, Tricorders & Sensors, Water/Hycean Worlds & Oceanography

Distinguishing Potential Organic Biosignatures on Ocean Worlds from Abiotic Geochemical Products using Thermodynamic Calculations

by Keith CowingMay 9, 2024May 9, 2024

The search for life in our solar system often involves efforts to detect organic molecules, which have been found on many extraterrestrial bodies, including planets, moons, meteorites, comets, and asteroids. […]

Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exploration Gear & Tech, Mars, Status Report, Tricorders & Sensors

Undecanoic Acid and L-Phenylalanine in Vermiculite: Detection, Characterization, and UV Degradation Studies for Biosignature Identification on Mars

by Keith CowingMay 8, 2024May 8, 2024

Solar radiation that arrives on the surface of Mars interacts with organic molecules present in the soil. The radiation can degrade or transform the organic matter and make the search […]

organic chemistry

UH Mānoa Scientists Help Unravel Life’s Cosmic Beginnings

An ALCHEMI Inspection of Sulphur-bearing Species Towards the Central Molecular Zone of NGC 253

Formation of N-bearing Complex Organic Molecules in Molecular Clouds: Ketenimine, Acetonitrile, Acetaldimine, and Vinylamine via the UV Photolysis of C2H2 Ice

Enceladus: Astrobiology Revisited

Tracing The Origins of Organic Matter in Martian Sediments

A New Theory To Explain The Origin Of Phosphorus

Early Replicators

Membrane Permeability Selection Drove the Stereochemistry of Life

Distinguishing Potential Organic Biosignatures on Ocean Worlds from Abiotic Geochemical Products using Thermodynamic Calculations

Undecanoic Acid and L-Phenylalanine in Vermiculite: Detection, Characterization, and UV Degradation Studies for Biosignature Identification on Mars

Isobaric Crystallization of Aqueous Magnesium Chloride Solutions at Icy Moon Conditions

Systematic Uncertainties in Rocky Exoplanet Reflected Light from Incomplete Laboratory BRDF Measurements

New Discovery Links Hemispheres In The Mystery Of Earth’s Past Ice Ages

UV Photodamage Pathways And The Evolutionary Selection Of Thymine Over Uracil In Early Genetic Systems

Reversion To The Meta Body Form Of Life After Complete Cell Death In Pure Liquid Water