The of begining life on earth

Discussion in 'Biology & Genetics' started by yaracuy, Feb 24, 2011.

  1. yaracuy Banned Banned

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    How life started or come in the planet earth.?
    How would I answer this question to my children ?
    I would like to have reasonable biochemical approach to my question
    Thank you.

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  3. ElectricFetus Sanity going, going, gone Valued Senior Member

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    Look up "abiogenesis" at present we do not have enough evidence for how life started on earth to back up any one theory.
     
    Last edited: Feb 24, 2011
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  5. spidergoat pubic diorama Valued Senior Member

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    Look up Martin & Russell's Alkaline Hydrothermal Vent hypothesis.

    http://journalofcosmology.com/Abiogenesis107.html

    ...microporous honeycombs have been shown to concentrate single nucleotides and oligomers of RNA and DNA up to thousands of times their starting concentration ..., a unique system making an RNA world plausible for the first time...
     
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  7. yaracuy Banned Banned

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    It is quite large paper it deserves some time to read , certainly it trows a lot of authors .
    It talks about RNA as catalyst, but one thing I was looking for is how do you get the nucleotides , how do you make them , what are your starting materials, to my understanding , there are about 6 or more step to make a nucleotide , beside you have to have ribose and to make it, it takes other more steps . So I would like to see a description on how to make those small molecules before we get to enzymes , RNA and DNA

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  8. ULTRA Realistically Surreal Registered Senior Member

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    To my knowledge, ribose is not a naturally occuring molecule, it takes life to make it. I was taught some years ago at Uni that the simplest life was formed by the formation of lipid membranes. These are fatty membranes made of oil, and can apparently form naturally from naturally occuring hydrocarbons derived from methane etc.
    Somehow, and I don't know how, simple systems managed to find a living converting chemicals thought to have been prevailent in and around hotwater vents known as black smokers. These still form and support some particularly bizarre life-forms. In fact, life in and around black smokers derive no energy whatever from the sun, and are totally independent of all other life on Earth.
    It is thought that these migrated up through the water column and over billions of years adapted to derive nourishment through sunlight as all photo-generic organisms do. The process of photosynthesis allows carbon dioxide and water to form sugars of which ribose is just one of many. This allows the building of other carbon-based molecules such as starch, used to store energy and cellulose used to build stronger cell-walls. All plant cells have cellulose cell walls, and animals still use lipids.
    The first life was not animal or vegetable as we now know it apparently, but more like a hybrid 3rd option. It's interesting to note that fungi follow none of these rules, and still do not derive thier energy directly from the sun.
    I think that's basically it in a nutshell. If I've made any error, I am certain someone will point it out to you.
     
  9. yaracuy Banned Banned

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  11. spidergoat pubic diorama Valued Senior Member

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  12. ULTRA Realistically Surreal Registered Senior Member

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    Latex is actually too advanced for the primative life we are talking about. It probably developed later in flowering plants as a defense measure against attack by insects.
    The manipulation of hysrocarbons and, notably sulphurous and phospherous compounds would allow for the reproduction of simple lipid cells. The beauty of these cells is they are hydrophobic on the outside and hydrophyllic on the inside allowing for a discreet cell apart from its environment. These lipids can also stand quite high temperatures which is useful if you're living off a hydrothermal vent. These can get as hot as 400 degrees C
    due to the depth and pressere.
     
  13. yaracuy Banned Banned

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    I can see the vents life on the outside of the vent were there will be a temperature gradient with distance were survival will be possible .
    I am not sure if a cell membrane ( phospholipid ) will not open at 50 C. otherwise it must be some Calcium or Magnesium based membrane.

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  14. yaracuy Banned Banned

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  15. ULTRA Realistically Surreal Registered Senior Member

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    The first organised life probably used something along the lines of MRNA due to its simplicity. The formation of enzymes and co-enzymes must have been a crucial developmental step both to process the chemicals in the environment and to reproduce. There is no direct evidence of this as far as I know, but For the first two bn years, life hardly seems to have changed at all. The development of transposable RNA must have been a crucial developmental step.
     
  16. ULTRA Realistically Surreal Registered Senior Member

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  17. ULTRA Realistically Surreal Registered Senior Member

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  18. yaracuy Banned Banned

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    MRNA do you mean Mitocondrea RNA . Well that is one of simple cell

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  19. yaracuy Banned Banned

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  20. ULTRA Realistically Surreal Registered Senior Member

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    Yes, that is correct. Although simple viral RNA is the most basic I know of. Some only has 40 or so active bases and have to hijack living cells to reproduce. My braincell is getting pretty hard-pressed fishing out this old stuff, but check the links and it should prove enlightening. If there is more i can help with let me know..
     
  21. ULTRA Realistically Surreal Registered Senior Member

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    As far as I know, it's lefthanded, but I'd have to check..
     
  22. yaracuy Banned Banned

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  23. ULTRA Realistically Surreal Registered Senior Member

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    Yes, the virus splits off a section 5Prime sticky, and inserts it into the host. The host then copies Trna and makes the protein for the virus, Damned sneaky unsportsmanly behaviour if you ask me. Did you know that ALL viruses are malignant? There is not one single virus ever found that actually helps anybody, they're all bad.
     

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