Wednesday, January 2, 2013

Cellular Machinery Redesigns Genes For Cold Temperature Operation

Really Cool

The central nervous system is constantly sending electronic impulses called action potentials which are propagated along nerve cells via the finely-tuned actions of various proteins that are located in the nerve cell’s membrane. First, there is a membrane protein that simultaneously pumps potassium ions into the cell and sodium ions out of the cell. This sets up a chemical gradient across the membrane. There is more potassium inside the cell than outside, and there is more sodium outside than inside. Also, there are more negatively charged ions inside the cell so there is a voltage drop (50-100 millivolt) across the membrane. In addition to the sodium-potassium pump, there are also sodium channels and potassium channels. These membrane proteins allow sodium and potassium, respectively, to pass through the membrane. They are normally closed, but when the action potential travels along the nerve cell tail, it causes the voltage-controlled sodium channels to open quickly. Sodium ions outside the cell then come streaming into the cell down the electro-chemical gradient. As a result the voltage drop is reversed and the decaying electronic impulse, which caused the sodium channels to open, is boosted as it continues on its way along the nerve cell tail. When the voltage goes from negative to positive inside the cell, the sodium channels slowly close and the potassium channels open. Hence the sodium channels are open only momentarily, and now with the potassium channels open, the potassium ions concentrated inside the cell come streaming out down their electro-chemical gradient. As a result the original voltage drop is reestablished. This process repeats itself until the impulse finally reaches the end of the nerve cell tail.

Not surprisingly this process is sensitive to conditions. Its sensitivity to temperature is mainly in the falling phase, when the original voltage drop is reestablished. This suggests that the potassium channels are more sensitive to temperature and researchers indeed discovered that extreme cold temperatures slows the closing of the potassium channels causing the action potential’s voltage profile to broaden and slowing the nerve cell’s capacity to transmit action potentials.

So how do organisms in extreme cold temperatures compensate? One might think that the potassium channels genes would be adapted, with the proper nucleotide substitutions that would lead to the proper modifications in the potassium channel protein.

But new research, examining octopus species in warm and cold regions, shows that the genetic differences are minor. As the paper explains:

On the basis of conventional natural selection, we hypothesized that the channels’ genes would have evolved mutations to help tune them to their respective environments. Surprisingly, the primary sequences encoded by the two genes were virtually identical, differing at only four positions.

So how do these cold temperature organisms adjust their potassium channels? As the paper concludes, by editing the RNA transcript, the so-called mRNA, of the gene:

the transcribed messenger RNAs are extensively edited, creating functional diversity. One editing site, which recodes an isoleucine to a valine in the channel’s pore, greatly accelerates gating kinetics by destabilizing the open state. This site is extensively edited in both Antarctic and Arctic species, but mostly unedited in tropical species

I just rearranged a sentence in this post. Imagine if I created a computer program to edit the text rather than me editing it manually? That is what these octopus species have, editing machinery to adjust the potassium channels genes automatically, after they are copied from the DNA and before they are translated into proteins. Wow.

21 comments:

  1. Minor correction-

    The nervous systems sends ELECTRIC impulses, not electronic impulses.

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  2. Of related interest to the use of electricity in biological processes:

    Proteins Conduct Electricity - November 25, 2012
    Excerpt: "The team showed that the protein could carry large currents, equivalent to a human hair carrying one amp. The team also discovered that current flow could be regulated in much the same way as transistors, the tiny devices driving computers and smartphones, work but on a smaller scale: the proteins are only a quarter of the size of current silicon based transistors."
    The finding represents a leap forward in measurement at the nano scale. “Prior to this work, measurement of millions, if not billions of proteins was only possible, so losing crucial details of how an individual molecule functions.” The team used scanning tunneling microscopy (STM) to read the electronics of a single molecule of cytochrome b562, a protein just 5 nanometers (billions of a meter) long.
    http://crev.info/2012/11/proteins-conduct-electricity/

    Of note: AWG 44 wire is the wire size that is equivalent to the width of a human hair,,

    Measurements and Gauge
    Excerpt: An AWG # 44 wire is about the thickness of a human hair.
    http://unimaxsupply.com/prc/pinstruct/measurements.htm

    And AWG 44 wire is rated at well below the .014 Ampacity, the last Ampacity they have listed, for AWG 40 wire,,,

    AWG Wire Table, AWG Copper Wire Gauge Chart
    http://www.interfacebus.com/Copper_Wire_AWG_SIze.html

    Thus, since 1 divided by .010 is 100, the ampacity (current carrying capacity) for the protein they measured is at least 100 times better than a copper or silver wire would be compared at the size of a human hair.

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    Replies
    1. Also of note: The best manmade (intelligently designed) conductor of electricity beats copper and silver by only 30 to 50 times:

      Graphene: How It Will Change the Future - Apr 12, 2012
      Excerpt: Copper is a great conductor of electricity and heat. Only silver beats copper (by less than 10%). That is why we use copper wires to transmit electricity and data, and copper pots are prized by cooks.
      Graphene conducts heat and electricity 30-50 times better than copper and silver: electrons flowing in graphene travel near the speed of light.
      http://finchin.com/graphene-in-plain-english/

      also of note:

      The mechanism and properties of bio-photon emission and absorption in protein molecules in living systems - May 2012
      Excerpt: From the energy spectra, it was determined that the protein molecules could both radiate and absorb bio-photons with wavelengths of less than 3 μm and 5–7 μm, consistent with the energy level transitions of the excitons.,,,
      http://jap.aip.org/resource/1/japiau/v111/i9/p093519_s1?isAuthorized=no

      Cellular Communication through Light
      Excerpt: Information transfer is a life principle. On a cellular level we generally assume that molecules are carriers of information, yet there is evidence for non-molecular information transfer due to endogenous coherent light. This light is ultra-weak, is emitted by many organisms, including humans and is conventionally described as biophoton emission.
      http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0005086

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  3. More surprised evolutionists falling off their chairs. The only thing not surprising is how often evolutionists are surprised.

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    Replies
    1. But evolutionists have a "one size fits all" theory, so there is not need to worry! :-)

      Delete
  4. Gee, there's an argument we've never seen before...

    "ZOMG it's so complicated, so therefore GAWDDIDIT!!!"

    Looks like 2013 is going to be another banner year for Intelligent Design Creationism "science".

    ReplyDelete
    Replies
    1. Resident evolutionist psycho Thorton:

      "ZOMG it's so complicated, so therefore GAWDDIDIT!!!"

      Complexity is the most perfect and effective argument against the farce of evolution. This is why the usual pathological liars like Thorton hate it so much. Order does not arise from chaos on its own. This is the reason that the air will never (zero probability) suddenly congregate in one corner of a room even though air molecules move around randomly. It is the reason that complex living organisms do not arise from dirt all by themselves.

      But don't tell that to the superstitious dirt worshipers. They're liable to start jumping up and down and foaming at the mouth. LOL.

      Delete
    2. Complexity is to a dirt worshiper what holy water is to a vampire.

      ahahaha...

      Delete
    3. Thorton,

      "Gee, there's an argument we've never seen before..."

      Here's a novel idea Thorton, why not try to come up with a reason why one should not employ complexity as an argument for design, rather than simply hand waving and saying it is not evidence for design.

      Complexity most certainly implies intelligence, simply asserting it does not need to come from intelligence is no argument at all.

      Delete
  5. Yes, another year where evolutionists give themselves a blank check to fill in whatever they feel they need at the moment to support ToE. We could find molecules writing sheet music for Handels Messiah on the underside of the cell membrane. Evolutionists would proceed to fall off their chair again and then go on to write how marveleous evolution must be. Blank check, signed EVEOLUUUUTIONDIDIT.

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  6. This precision mechanism of self-modification was brought to you by random mutation and natural selection. Call now to place your orders on the Brooklyn bridge.

    ReplyDelete
  7. Don't you get it? The new naturalistic explanation just IS atheistic explanation. It's no longer what it used to be--blind efficient causality producing specific events in terms of event regularities applied to conditions at some time.

    It can now be teleological. It can involve what for all the world seems to be foresight. It just can't involve a designer. It can know how to satisfy the constraints of future tree-generation without any dependence on event regularities (i.e., determinism).

    Moronton has told us, since his priest Gould said it, that evolution will happen different every time even starting with the same initial conditions (no event regularities involved in the event specificity, in other words). And yet no matter how differently it might choose to proceed, it knows to land in a cladistic tree millions of years later, per human tree-generating criteria.

    How can one argue with such sheer oblivion. They're attributing all the attributes of mind to the concept "biological evolution" and pretending their doing something different than teleological explanation. Whether they call it a designer is absolutely irrelevant. They're just too oblivious to realize that's all they're doing.

    ReplyDelete
    Replies
    1. Poor Liar for Jesus Jeff. Still whining about the science he doesn't understand, still trying to use his worthless philosophy training to overturn verified scientific findings.

      That's alright LFJJ. Just keep sucking that pacifier and cry yourself to sleep. Maybe someone will pay attention to your puerile blathering someday.

      Delete
    2. This comment has been removed by the author.

      Delete
    3. You pay enough attention to my posts to count as a fan-club, Moronton.

      Delete
    4. Liar for Jesus Jeff

      You pay enough attention to my posts to count as a fan-club


      LOL! I watch out for dog crap so I don't step in it too.

      Keep sucking that pacifier LFJJ, make the mean old scary evolutionary science go away!

      Delete
    5. A fan-club of one. But enthusiastic to the bone marrow.

      Delete
    6. Thorton,

      "That's alright LFJJ. Just keep sucking that pacifier and cry yourself to sleep. Maybe someone will pay attention to your puerile blathering someday."

      How about trying to answer the question for a change, rather than hurling insults.

      Delete
    7. Thorton,

      "Keep sucking that pacifier LFJJ, make the mean old scary evolutionary science go away!"

      We don't need to do anything to make the oxymoron 'evolutionary science' go away, it's dieing all on its own. Like all lies it's becoming weighed down by its inordinate need to maintain itself.

      The inevitable fate of all lies is that the subsequent lies needed to preserve the initial lie soon overwhelm it.

      Delete
  8. This comment has been removed by the author.

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  9. If editing machinery to adjust the potassium channels genes automatically, after they are copied from the DNA and before they are translated into proteins. NDT Machine

    ReplyDelete