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C13 to C12 Ratio of Natural and Synthetic Testosterone
In article ,
Geraard Spergen wrote: C12 is 99% of all carbon, C13 is 1%, and C14 is about 1 part per 10^12. Plants naturally have more C13 than animals so any substance (including testosterone) produced from plants will have a higher C13 proportion than the same substance produced by animals. Hard to believe there's any difference in chemical reactions, it's probably due to photosynthesis. What is photosynthesis if not a chemical reaction? At least make your beliefs consistent. I suggest you take up creationism. If that is not to your liking you will have to eat your beliefs, because we have known for many decades that chemical reaction rates for C12, C13, and C14 are different. -- Michael Press |
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C13 to C12 Ratio of Natural and Synthetic Testosterone
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C13 to C12 Ratio of Natural and Synthetic Testosterone
Michael Press wrote:
In article , Geraard Spergen wrote: C12 is 99% of all carbon, C13 is 1%, and C14 is about 1 part per 10^12. Plants naturally have more C13 than animals so any substance (including testosterone) produced from plants will have a higher C13 proportion than the same substance produced by animals. Hard to believe there's any difference in chemical reactions, it's probably due to photosynthesis. What is photosynthesis if not a chemical reaction? At least make your beliefs consistent. I suggest you take up creationism. If that is not to your liking you will have to eat your beliefs, because we have known for many decades that chemical reaction rates for C12, C13, and C14 are different. Oh man, that's harsh! Differing chemical reaction rates cannot explain why plants have more C13 to begin with. You have to explain why C13 is more likely to become part of a plant than to become part of something else... or perhaps you could propose that flora C12 is more likely to absorb an itinerant neutron than fauna C12. Chemistry is mostly about electrons, photons are absorbed in the nucleus. I reasoned (perhaps incorrectly) that photosynthesis involves photons being absorbed by neutrons and that C13 had a higher cross section for photon absorption than did C12 and that this might account for plants having a higher proportion of C13 than non-photosynthesizing organisms. It may be a dumbass theory, but it can't hold a candle to creationism. |
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C13 to C12 Ratio of Natural and Synthetic Testosterone
Geraard Spergen wrote:
Differing chemical reaction rates cannot explain why plants have more C13 to begin with. You have to explain why C13 is more likely to become part of a plant than to become part of something else... or perhaps you could propose that flora C12 is more likely to absorb an itinerant neutron than fauna C12. Chemistry is mostly about electrons, photons are absorbed in the nucleus. I reasoned (perhaps incorrectly) that photosynthesis involves photons being absorbed by neutrons and that C13 had a higher cross section for photon absorption than did C12 and that this might account for plants having a higher proportion of C13 than non-photosynthesizing organisms. It may be a dumbass theory, but it can't hold a candle to creationism. Photosynthesis is about chlorophyll absorbing multiple red photons and using that sum energy to cleave water and co2 to make sugar, sort of. Photons in the visible region are mainly absorbed by the electrons in the bonding orbitals of the molecules (or the outer electrons for atoms (inner electronic transitions are generally in the x-ray/vuv region for atoms)). Nuclear spin transitions, I vaguely recall, can be in the visible region, but their transitions strengths are weak and nearly always visible spectra of atoms and molecules are determined by the electronic structure. Nuclear energy transitions are up in the gamma ray region. Anyway, I am too lazy to look this next bit up but I think it is more or less correct, the thing about chlorophyll that is interesting is that it absorbs photons and transfers that energy into vibrational modes. That vibrational energy builds up in the porphin ring and is then used to initiate breaking apart of CO2 and H2O. Or something like that anyway. Biologically produced carbon compounds have *less* of the heavier isotopes, not more. Isotopic fractionation occurs because in general heavier things don't move as fast (both in a vibrational sense and in a translational sense) and it is the kinetic energy of motion, to a large degree, that makes molecules react. There is sort of a double whammy for plants in that the CO2 fractionates going through the stoma since the 13CO2 is not as efficiently transported into the plant to begin with, this is mainly a translational effect. Once in the plant, the heavier isotope CO2 doesn't react as readily (which I think is the vibrational effect). -- Bill Asher |
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C13 to C12 Ratio of Natural and Synthetic Testosterone
Ron Ruff wrote: wrote: Does anyone know how much the difference is? And better yet, why is there a difference? From a NYTimes article posted to ST: "The test starts with an isolation of testosterone from the athlete's urine. Then chemists determine the makeup of the carbon atoms that form the backbone of testosterone. Ordinarily, carbon atoms are made up of six protons and six neutrons, giving them an atomic weight of 12. But occasionally, they have an extra neutron, giving them an atomic weight of 13. By chance, soy plants are the source of most pharmaceutical testosterone. They tend to have slightly less carbon-13 than other plants that are more abundant in the human diet. Humans make testosterone from the food they eat, so their testosterone typically has more carbon-13 than the testosterone that drug companies synthesize from soy. But these differences are tiny. The test determines whether the testosterone in the athlete's urine has less carbon-13 than another naturally occurring hormone in the urine, like cholesterol. The test is considered positive when the carbon isotope ratio - the amount of carbon-13 compared to carbon-12 - is three or more units higher in the athlete's testosterone than it is in the comparison hormone. It is evidence that the testosterone in the urine was not made by the athlete's body. Landis's difference was 3.99, according to his own doctor." For the purpose of discusion, I will accept everything you say. The problem I have is that WADA/UCI have not produced a study of an appropriate sized sample, say 100 or 1,000, which was tested blind. In the study technicians would given samples of unknown content (to them) and told to identify which of the samples had exogenous T and which did not.. Of course many of the samples would have idential composition, and be given to different individuals (from different labs). Then the resulting data should be made known to the public so it can be reveiwed and commented upon. Said another way, describing a complex test does not answer the question "does the test actually do what it is claimed to do." The thrust of the machine manufacturer's comments is the answer is "no." |
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C13 to C12 Ratio of Natural and Synthetic Testosterone
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C13 to C12 Ratio -- Is Floyd a Vegetarian?
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C13 to C12 Ratio of Natural and Synthetic Testosterone
On 2 Aug 2006 15:52:35 -0700, "gds" wrote:
But then you want the "public" to comment. On what would the public comment? Of what value would it be? The discussion is about highly technical and complex procedures. Of what use would my degree in economics be in judging the worth of these studies. Yes, with a bit of logic one can see summary results and make a dilletantish judgement but not a really scientific judgement. I sure don't put much stock in a chemist's opinion of my currency exchange rate prediction model. But a lot of other economists have liked it. There's room for cross-discipline opinion. Too often a field will be so caught up in its own assumptions that it won't see what is obvious from another perspective. You are economist, you've seen this happen in your field in your life time. Now that chemist knows his limitations (only if he's smart and honest) and could only ask the sort of questions that a really bright guy who understands science in general could put to you about your model. But, I'm sure you could see that he might have a worthwhile perspective on it. Ron |
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C13 to C12 Ratio of Natural and Synthetic Testosterone
In article ,
Geraard Spergen wrote: Michael Press wrote: In article , Geraard Spergen wrote: C12 is 99% of all carbon, C13 is 1%, and C14 is about 1 part per 10^12. Plants naturally have more C13 than animals so any substance (including testosterone) produced from plants will have a higher C13 proportion than the same substance produced by animals. Hard to believe there's any difference in chemical reactions, it's probably due to photosynthesis. What is photosynthesis if not a chemical reaction? At least make your beliefs consistent. I suggest you take up creationism. If that is not to your liking you will have to eat your beliefs, because we have known for many decades that chemical reaction rates for C12, C13, and C14 are different. Oh man, that's harsh! Differing chemical reaction rates cannot explain why plants have more C13 to begin with. You have to explain why C13 is more likely to become part of a plant than to become part of something else... or perhaps you could propose that flora C12 is more likely to absorb an itinerant neutron than fauna C12. Chemistry is mostly about electrons, photons are absorbed in the nucleus. I reasoned (perhaps incorrectly) that photosynthesis involves photons being absorbed by neutrons and that C13 had a higher cross section for photon absorption than did C12 and that this might account for plants having a higher proportion of C13 than non-photosynthesizing organisms. It may be a dumbass theory, but it can't hold a candle to creationism. But look, you are `reasoning' from your beliefs. Chemical reaction rates are also about mobility of reactants. That C13 is heavier than C12 affects its mobility. Bill*Asher talks about some details; to which I add that respiration, glycolysis, and photosynthesis are largely reversible reaction sequences in which single step fractionations are additive leading to a much increased discrimination factor for the overall process. This situation is analogous with the high efficiency with which a multiple-plate fractionating column effects the separation of liquids differing only slightly in their vapor pressures when a single distillation step achieves but little separation. -- Michael Press |
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