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Cellular Membranes

  1. May 12, 2008 #1
    This is the only question I would like an answer to..I'm asking this partly because i just read this http://www.fightaging.org/archives/001227.php

    I was wondering theoretically (ie in the future but with technology that we can currently think about) could cellular energy be produced in a different way- ie via artificial mitochondria and could there be some way to bypass the need for mitochondria/some other way to give the cell adenosine triphosphate and why or why not..thanks
     
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  3. May 12, 2008 #2

    Andy Resnick

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    Cells (and mitochondria) generate useful work by exploting the non-equilibrium thermodynamics of living matter. For example, ATPases do not liberate useful work by cleaving a "high energy phosphate bond". Rather, the concentration [ATP]/[ADP] is so far out of equlibrium that the cell exploits the chemical potential change by converting one ATP molecule into ADP.

    In the mitochondrial and cellular membranes, there is equivalence between chemical (osmotic) gradients and electrical potential gradients. One is freely converted into another. This is how the cell stores energy, how the action potential works, and is at the origin of respiration.

    There's nothing special about ATP per se- GTP is used by many signalling molecules (G-proteins), and IIRC is part of the nuclear trafficking.

    Cellular energy arises from the out-of-equilibrium dynamics required to sustain a biological system.
     
  4. May 12, 2008 #3
    I can try to understand that but in simpler terms, with foreseaable technology Could something other than the mitochondria be used to serve the purpose that mitochondria serves to help the cell's survival? Is it possible a cell wouldn't need the mitochondria to survive? Could you just answer yes or no?
     
  5. May 12, 2008 #4

    jim mcnamara

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    In simple terms, you want to replace the organelle that produces energy for all cell operations with something else (that does not make harmful by products == my inference). Since you ask 'in the future' nobody can give a definite answer. As a guess - possibly.

    But, since eucaryotic cells have persisted since before the Cambrian, mitochondria and other organelles must have passed the test of time. You do realize that mammalian ageing and subsequent death is something that has also passed a similar test. To my knowledge lifespans in mammals of any species seldom exceed 100 years. Humans included.

    Once humans have succesfully reproduced, there is no selection pressure on non-reproducing older humans to prevent them from ageing and becoming physically or mentally less than what they were earlier. But. They can still pass on their genes by helping someone else's (like a relative or offspring) young to survive. This is the thoery of kin selection. See:
    http://www.iscid.org/encyclopedia/Theory_of_Kin_Selection
     
  6. May 12, 2008 #5
    Would we be able to guess how replacing the organelle that produces energy for all cell operations with something else that does not produce free radicals could work or would that be too far in the future?

    Also do stem cells turn into the types of cells in their environment without turning into a cell that's identical to the ones in their environment? Ie I know they would acquire DNA damage just like any other type of cell would, but would they turn into a cell with oxidative DNA damage because the cells in their environment would have oxidative DNA damage, and they would be mimicking that? Or would they not?

    I'm definitely not saying/thinking that there is a way to really extend human lifespan a whole lot but it's still interesting to me to think about/try to find out about
     
  7. May 12, 2008 #6
    also theoretically what's the most could you replace the brain with adult/embroynic stem cells? Why? (Disregarding things like memory problems etc)
     
  8. May 12, 2008 #7
    Never mind my friend just kind of answered all my questions
    I'd still like to think that in the future we could have the technology to bring someone back from being cryogenically frozen and to help them
     
  9. May 12, 2008 #8
    If we were able to produce younger blood (ie by changing our genes or something) for our entire lives though, could that help with DNA damage? how? Having white blood cells would help with inflammation I guess but in what other ways could it help with DNA damage? Also does this destroy free radicals or just detect them? http://sciencelinks.jp/j-east/article/200207/000020020702A0250809.php ignore all the other questions since my friend helped me with them..
     
    Last edited: May 12, 2008
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