Underground anaerobic life

Discussion in 'Biology & Genetics' started by timojin, Feb 19, 2016.

  1. timojin Valued Senior Member

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    What is the mechanism for anaerobic life ?
     
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  3. Yazata Valued Senior Member

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    Cellular respiration consists of a chain of electron transport molecules, each of which which has an electrochemical gradient to the others. Electrons pass from molecule to molecule and energy is extracted at each step, which is used to synthesize adenosine triphosphate (ATP), which stores the energy extracted and serves as the fuel of the cell, powering its other activities. At the end of the chain, the electrons have to go somewhere and in aerobic organisms, O2 serves as the final electron acceptor. Oxygen works well in this role since it maintains a huge electrochemical gradient and lots of ATP producing steps can fit ahead of it.

    But other molecules can accept electrons too, if less efficiently. In methanogens, CO2 accepts the electrons and methane is produced as a biproduct. This is one of the sources of cow-farts. In some organisms, sulfates accept the electrons and hydrogen sulfide is produced as a biproduct. This is where that rotten-egg smell of sewer gas comes from.

    There are many other possibilities as well.

    https://en.wikipedia.org/wiki/Anaerobic_respiration

    The problem with anaerobic respiration is that it isn't as efficient as aerobic respiration and produces fewer ATP molecules.

    Anaerobic organisms can either be facultative anaerobes or obligate anaerobes. Facultative anaerobes are capable of aerobic respiration in the presence of oxygen, but can switch over to some form of anaerobic respiration if oxygen is in short supply. Many prokaryotes (bacteria and archaea) are facultative anaerobes. Obligate anaerobes must respire anaerobically and can't survive in the presence of oxygen. (Oxygen is highly reactive and oxidation is very corrosive to biochemistries that aren't adapted to tolerate and exploit it.) These obligate anaerobes were probably the ancestors of all the aerobes and existed on the Earth before the Earth's atmosphere possessed large amounts of O2. They still exist today here and there, in environments where oxygen isn't found. Anaerobic respiration isn't as efficient as aerobic respiration, but there aren't any aerobic organisms in these anaerobic environments to compete with the anaerobes.
     
    Last edited: Feb 20, 2016
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  5. Waiter_2001 Registered Senior Member

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    Counting!
     
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  7. timojin Valued Senior Member

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  8. timojin Valued Senior Member

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    Does in the anaerobic process bacteria reduces Fe2O3 2Fe+++ + 2e------ to 2Fe++ + + O2 if so then in order to have Oxygen, life must exist and live in an anaerobic world
     
  9. Waiter_2001 Registered Senior Member

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    But if oxygen didn't exist life would exist in some other form.

    "Life finds a way"-Jurassic Park!
     
  10. timojin Valued Senior Member

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    I will believe if life will be found on Mars
     
  11. Waiter_2001 Registered Senior Member

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    What about if Astronauts from Earth travel to said planet? Life on Mars!

    Please Register or Log in to view the hidden image!

     
  12. timojin Valued Senior Member

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    Let them go and drop their pants and shit on the ground and bury it then come back and check it out . then perhaps will discover life on Mars.
     
  13. exchemist Valued Senior Member

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    My understanding is that certainly anaerobic life (deriving energy from oxidation reactions that do not involve free molecular oxygen) would have had to precede aerobic life, as there would not have been free oxygen in the atmosphere of the early Earth. Photosynthesising organisms would then at some stage have started to create the free oxygen in the air on which the later aerobic life depended.
     
  14. timojin Valued Senior Member

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    As you mention aerobic. like plants . it would be necessary to create a molecule like porphyrin, so I wonder if anaerobic bugs have an assembly like is porphyrin , or they have molecules like pyrrole ?
     

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