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23 Cards in this Set
- Front
- Back
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Geobiology |
Explores interactions between the biosphere and lithosphere or atmosphere |
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Geomicrobiology |
Investigates the interactions between microbes and minerals |
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Chemolithotrophs |
Organisms that utilize inorganic energy sources |
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H2 Oxidizers |
Link the oxidation of hydrogen to some electron acceptor Done via hydrogenase enzymes Many organisms have this enzyme, so it is a widespread metabolism Occurs in both oxic and anoxic environments |
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Sulfur Oxidizers |
Oxidize hydrogen sulfide, elemental sulfur, or thiosulfate Found at interfaces of anoxic and oxic condition Can be acidophiles or neutral environments |
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Iron-Oxidizing Bacteria |
At neutral pH, Ferrous to Ferric is rapid In acid (acid mine drainage), abundant Fe(II), can be used as electron acceptor |
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Acetogens |
Use H2 as a donor to fix CO2 into acetate in which they can use for growth |
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The Hadean Eon |
4.4 to 4 Billion years ago Heavy bombardment from space debris No continents, no oceans |
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Hadean Atmosphere |
UV, radiation, redox state Atmosphere: 1000x as much CO2 and SO2 No O2 or O3 Lots of CO and smog >100 C Sun 30% less bright |
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Primordial Oceans |
It is thought that the Earth acquired 10^21 L of H2O (current V of oceans) between 4.5 and 3.8 billion years ago from comet collisions alone. |
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Landmass |
Molten materials at the surface of earth; extensive offgassing of volatiles led to primordial atmosphere |
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Landmass in the Hadean |
In the Hadean—large amounts of tectonic recycling resulted in the release of large amounts ofmantle carbon into the atmosphere. Atmosphere probably CO>CH4>CO2 and a lot of H2. |
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Astrobiology |
The study of the origin, evolution, distribution, and future life in the universe Combines aspects of astronomy, biology, and geology. |
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Astrobiology seeks to answer... |
How does life begin and evolve? Is there life beyond earth, and if so, how can we detect it? What is the future of life on earth and in the universe? |
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Origin of Life |
1. Hadean Ocean: warm little pond of organic monomers = Primordial Soup 2. Hydrothermal vents: could be the location of the first life forms 3. Panspermia: Life originated from microorganisms or chemical precursors deposited by asteroids or comets |
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Organic Soup |
Miller's Experiment: Reduced gases (CH4, H2, H2O, NH4) with lightening produces amino acids. Think Energy: Chemical Radiation Ultraviolet Physical (bombardment: massive lava flows, water, etc) |
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Hydrothermal |
Thermal and chemical disequilibrium is the key! Serpentinization of ultra-mafic crust, water + iron, produced abundant H2 Hot, reduced rising waters hit cool, potentiallyoxidized waters, for subsequent dispersed mixing plumes. That gives both thermal and chemicalgradients, and, thermodynamic availability of ‘nutrients’ for life. |
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Exergonic |
Of a metabolic process accompanied by the release of energy (Reactants > Products) |
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Endergonic |
Of a metabolic process requiring the absorption of energy (Products > Reactants) |
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What life needs in order to form exergonically.. |
Lipids (Self sealing, envelopes) Amino Acids Polysaccharides (Structural) Proteins (catalysts, energy, structure) Nucleic Acids (replication, information transfer) |
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LUCA |
Chemolithoautotroph Energy Source: chemo = chemical reactions photo = electromagnetic radiation (photons) Electron Donor: litho = inorganic compounds organo = organic chemicals Carbon Source: auto = inorganic carbon hetero = organic carbon Troph = eater |
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Magnetite |
Several magnetic iron minerals are biomineralized by different microbes. Can form in 2 ways: Biologically induced mineralization and Biologically controlled mineralization |
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Biologically induced mineralization (BIM) |
Not controlled by the organism. |
