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Distribution of isotopes throughout the body

  1. Mar 25, 2006 #1
    Are different carbon, e. g., isotopes distributed throughout the human body in relatively different concentrations? Are radioactive atoms mutagenic and electronically dissimiliar, thus affecting the chemistry of neighboring structures? Could these isotopes be a considerable source of DNA diversity?
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  3. Mar 27, 2006 #2


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    Natural Radioactivity in the Body

    There is natural background radioactive isotopes in our body.
    Natural Radioactivity in the Body ( ref)
  4. Mar 27, 2006 #3
    I wonder if the net radiation from the human body compares to that impinging upon it from the exterior environment?
  5. Mar 30, 2006 #4
    What do you mean by this? If different isotopes are in different concentrations in different places in the body? Can you please clarify?

    Yes, mutations can occur by radiation, but only in relatively large quantities. The normal background radiation is much much more stronger than any radiation that come from naturally occuring elements, that you would normally take in. Even radiation from future fusion plants would be about 1% of the current background radiation.

    However, if you eat a kilogram of weapongrade uranium U-235 you would indeed be subjected to..well...death.
    As a result, no.
  6. Mar 30, 2006 #5
    Depending upon where you live, about 5/6 of your roughly 360 mrem background exposure comes from natural sources, and about 200 mrem of this comes from radon.
  7. Mar 30, 2006 #6
    For instance, in the evolution of grasses first one isotope of carbon (designated C3) was common, then another (C4). I thought that different isotopes in general might perform different functions in human tissue or DNA as well.
  8. Mar 31, 2006 #7


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    C3 and C4 are not isotope. These refers to the amount of carbon on the sugar synthesized by the plant.

  9. Mar 31, 2006 #8
    Plus, different isotopes are chemically identical, that is, a radioactive C14 atom is no different for chemical reactions than a non-radioactive carbon atom. Chemical behavior is determined primarily by the electrons in the outer shell, which is why elements are divided into periods.
  10. Mar 31, 2006 #9
    Besides, Carbon-14 decay is only for beta radiation (and not gamma which would have any effect at all).
  11. Apr 1, 2006 #10
    If you all have the opportunity, see the bottom half of page 230 in the popular (and scientific) book "Beasts of Eden," about mammal evolution. Its author, David Rains Wallace, seems to have made a major gaffe with the term "isotope" in reference to carbon in grasses.

    Aside: I believe that deuterium may have significant chemical differences with common hydrogen.
  12. Apr 2, 2006 #11


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    The chemical properties should be identical. The thing that contributes to their difference is that Deuterium has a larger mass so, for example, reactions involving Deuterium might proceed at a slower rate than those involving Hydrogen.
  13. Apr 2, 2006 #12


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    Isotope effects: compounds containing lighter isotopes exhibit slightly higher rate constants in chemical reactions; that is, 12C, 13C, and 14C abundances (measured in ppm enrichments or depletions of 13C, and 14C) differ in bio-mass from those of C from other sources.
  14. Apr 2, 2006 #13
    Thanks all for your addenda.

    I figure that C3 and C4 are actually isomers of molecular carbon, whence a misprint by "Beasts of Eden."
  15. Apr 16, 2006 #14
    They're not isomers either. C3 plants initially incorporate carbon into a 3-carbon molecule, while C4 plants incorporate it into a 4-carbon molecule. There are also many other anatomical and physiological differences between the two types of plants.
  16. Apr 16, 2006 #15
    Looks like you have the definitive answer, nipwoni.
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