History Main / MirrorChemistry

11th Jul '17 6:16:47 PM MarqFJA
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Most of the molecules required for life have the property known as [[http://en.wikipedia.org/wiki/Chirality_(chemistry) chirality]] or "handedness". That is, they are not the same as their mirror image, like a left shoe which will not fit properly on your right foot no matter how you rotate it. That wouldn't have been that much of a problem, if not for the one insignificant fact that most of the stuff our bodies are made of, mainly the amino acids, which are the building blocks for the proteins we consist of, are chiral. And ''all'' multicell organisms on Earth are made of L-(or levo-)amino acids.[[note]]This is not to be confused with the molecule's optical activity: that is, if we shine a light through its solution, l-isomer will rotate its polarization plane (a plane the EM-wave is oscillating) to the left, that is, counter-clockwise, and d-isomer, or dextrorotatory one, will do it to the right, or clockwise. Many L-isomers are in fact l- (or (-), as chemists now prefer to designate them) isomers, and vice versa, but it's not true for all of them.[[/note]] Dextro-amino acids (except cysteine) are exceedingly rare in Earth organisms and are used only by some bacteria and in a few very specialized cases by larger creatures. Referencing this fact is a fairly common way for science-fiction writers to ShowTheirWork. It generally comes up in one of two situations:

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Most of the molecules required for life have the property known as [[http://en.wikipedia.org/wiki/Chirality_(chemistry) chirality]] or "handedness". That is, they are not the same as their mirror image, like a left shoe which will not fit properly on your right foot no matter how you rotate it. That wouldn't have been that much of a problem, if not for the one insignificant fact that most of the stuff our bodies are made of, mainly the amino acids, which are the building blocks for the proteins we consist of, are chiral. And ''all'' multicell multicellular organisms on Earth are made of L-(or levo-)amino acids.[[note]]This is not to be confused with the molecule's optical activity: that is, if we shine a light through its solution, l-isomer will rotate its polarization plane (a plane the EM-wave is oscillating) to the left, that is, counter-clockwise, and d-isomer, or dextrorotatory one, will do it to the right, or clockwise. Many L-isomers are in fact l- (or (-), as chemists now prefer to designate them) isomers, and vice versa, but it's not true for all of them.[[/note]] Dextro-amino acids (except cysteine) are exceedingly rare in Earth organisms and are used only by some bacteria and in a few very specialized cases by larger creatures. Referencing this fact is a fairly common way for science-fiction writers to ShowTheirWork. It generally comes up in one of two situations:
30th Jun '17 1:31:34 AM bfunc
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* Receptors for proteins, hormones, and other organic chemical compounds are made to fit certain molecular structures of a certain chirality. If a molecule does not have the correct chirality, it doesn't fit in the receptor, or worse, can actively harm the organism. As if that's not enough, the human body can sometimes metabolize a useful structure into its harmful mirror image. This was what happened with Thalidomide - a certain chiral structure (also called an enantiomer) of the compound was useful for the effects of morning sickness in pregnant women, but the other enantiomer of it caused terrible birth defects. The early testing of the compound was performed on just the desired enatiomer, but the mass-production synthesis method produced a racemic form. This is also the case with the cancer-fighting drug Platinol, which only causes sickness because scientists can't separate the helpful enantiomer of the drug from the toxic one, so it's sold as a mixture of the two (any mixture of both enantiomers of a compound is called a racemic mixture).

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* Receptors for proteins, hormones, and other organic chemical compounds are made to fit certain molecular structures of a certain chirality. If a molecule does not have the correct chirality, it doesn't fit in the receptor, or worse, can actively harm the organism. As if that's not enough, the human body can sometimes metabolize a useful structure into its harmful mirror image. This was what happened with Thalidomide - a certain chiral structure (also called an enantiomer) of the compound was useful for the effects of morning sickness in pregnant women, but the other enantiomer of it caused terrible birth defects. The early testing of the compound was performed on just the desired enatiomer, but the mass-production synthesis method produced a racemic form.form (Note that ScienceMarchesOn ... this story is probably still told to first year organic chemistry students as a cautionary tale about the importance of chirality, but it turns out that thalidomide racemizes ''in vivo'' and even if the testing was done with one chirally pure form, some of it would have converted to the other enantiomer as soon as it was taken). This is also the case with the cancer-fighting drug Platinol, which only causes sickness because scientists can't separate the helpful enantiomer of the drug from the toxic one, so it's sold as a mixture of the two (any mixture of both enantiomers of a compound is called a racemic mixture).
30th Jun '17 1:12:15 AM bfunc
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* In ''[[Literature/AliceInWonderland Through the Looking Glass]]'', Alice speculates that looking-glass milk might not be good to drink. This is probably the UrExample; in fact, it predates the coining of the word "chirality" by several years. In ''The Annotated Alice'', Martin Gardner discusses the chemical reasons why this would be true, before moving on to point out that looking-glass milk would likely be made of antimatter, making it ''[[StuffBlowingUp really]]'' bad to drink.

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* In ''[[Literature/AliceInWonderland Through the Looking Glass]]'', Alice speculates that looking-glass milk might not be good to drink. This is probably the UrExample; in fact, it predates the coining of the word "chirality" by several years. In ''The Annotated Alice'', Martin Gardner discusses the chemical reasons why this would be true, before moving on to point out that looking-glass milk would likely be made of antimatter, antimatter[[note]]probably not, because if the milk were antimatter everything else in the looking-glass world would be too, and Alice wouldn't have lived long enough to wonder about it[[/note]], making it ''[[StuffBlowingUp really]]'' bad to drink.
24th Jun '17 1:08:47 PM Ferot_Dreadnaught
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** Also played GenreSavvy by big pharmaceutical companies. A company will frequently develop and market a medication consisting of some compound in a racemic mixture, sell that until its patent exclusivity expires, and then release a "new" medication consisting of only the biologically active enantiomer of the original compound, so as to gain a whole new patent life for essentially the same compound. A good clue to this tactic is a generic drug name that looks like the original with a S or D added. Examples include Prilosec (omeprazole) vs. Nexium (esomeprazole), Celexa (citalopram) vs. Lexapro (escitalopram), Claritin (loratadine) vs. Clarinex (desloratadine), and so on.

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** Also played GenreSavvy by big pharmaceutical companies. A company will frequently develop and market a medication consisting of some compound in a racemic mixture, sell that until its patent exclusivity expires, and then release a "new" medication consisting of only the biologically active enantiomer of the original compound, so as to gain a whole new patent life for essentially the same compound. A good clue to this tactic is a generic drug name that looks like the original with a S or D added. Examples include Prilosec (omeprazole) vs. Nexium (esomeprazole), Celexa (citalopram) vs. Lexapro (escitalopram), Claritin (loratadine) vs. Clarinex (desloratadine), and so on.
9th Apr '17 10:05:12 PM BillyDaRed
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** If a female Shepard romances her turian teammate Garrus, Dr. Mordin Solus warns her against swallowing turian semen.
** Also, if a male Shepard romances his quarian teammate Tali, Dr. Mordin Solus says; "Oral contact with tissue dangerous. Take precautions." This could be a warning against swallowing quarian vaginal fluids, advice to not let Tali swallow human semen, or both.

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** This comes up in the second game if you want to romance your dextro-based squadmates. If a female Shepard romances her turian teammate Garrus, Dr. Mordin Solus warns her against swallowing turian semen. \n** Also, if If a male Shepard romances his quarian teammate Tali, Dr. Mordin Solus says; "Oral contact with tissue dangerous. Take precautions." This could be a warning warns him against swallowing quarian vaginal fluids, advice to not let Tali swallow human semen, unprotected oral sex (for Tali's sake, Shepard's sake or both.both).
26th Jan '17 1:10:23 AM Xtifr
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* The Creator/IsaacAsimov short story "Left to Right" has a scientist create a device that will apply some sort of directional interchange on whatever passes through; the scientist intends to use himself as a test subject. There is a discussion about potential issues if he ends up with his heart on the wrong side or unable to eat because of wrong-handed proteins, but he plans on reversing himself again before that becomes an issue. It turns out not to matter; the device actually just [[spoiler:[[{{Feghoot}} changes the scientist's name from Robert L. Forward to Robert L. Backward.]]]]

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* The Creator/IsaacAsimov short story "Left to Right" has a scientist create a device that will apply some sort of directional interchange on whatever passes through; the scientist intends to use himself as a test subject. There is a discussion about potential issues if he ends up with his heart on the wrong side or unable to eat because of wrong-handed proteins, but he plans on reversing himself again before that becomes an issue. It turns out not to matter; the device actually just [[spoiler:[[{{Feghoot}} changes the scientist's name from Robert L. Forward Creator/RobertLForward to Robert L. Backward.]]]]
1st Aug '16 6:45:10 PM Morgenthaler
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* ''TourOfTheMerrimack'': The crew aren't worried about picking up any diseases in the Myriad because life on those worlds uses opposite-handed proteins, which are are incompatible with human biology. It's likened to attempting to attach a four-post wheel to a five-post axle with opposite-thread bolts. It is also mentioned that [[HordeOfAlienLocusts the Hive]] is unique among all known species in that it is able to digest proteins of either chirality.

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* ''TourOfTheMerrimack'': ''Literature/TourOfTheMerrimack'': The crew aren't worried about picking up any diseases in the Myriad because life on those worlds uses opposite-handed proteins, which are are incompatible with human biology. It's likened to attempting to attach a four-post wheel to a five-post axle with opposite-thread bolts. It is also mentioned that [[HordeOfAlienLocusts the Hive]] is unique among all known species in that it is able to digest proteins of either chirality.



* In the ArthurCClarke short story "Technical Error", an experimental superconducting power station accidentally inverts Richard Nelson so that all his body chemistry is opposite-handed. He needs to have special "left-handed" food synthesized for him, and since no one is sure if we've missed any essential micronutrients that would also need to be inverted for him, he figures his best option for long-term survival is to repeat the accident and try to re-invert himself.

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* In the ArthurCClarke Creator/ArthurCClarke short story "Technical Error", an experimental superconducting power station accidentally inverts Richard Nelson so that all his body chemistry is opposite-handed. He needs to have special "left-handed" food synthesized for him, and since no one is sure if we've missed any essential micronutrients that would also need to be inverted for him, he figures his best option for long-term survival is to repeat the accident and try to re-invert himself.



* An episode of BlackHoleHigh was actually called "Chirality," and introduced the concept in a chemistry class -- then used it as a justification for a PersonalitySwap episode.

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* An episode of BlackHoleHigh ''Series/BlackHoleHigh'' was actually called "Chirality," and introduced the concept in a chemistry class -- then used it as a justification for a PersonalitySwap episode.



* In ''{{GURPS}} Time Travel'', this is one of the entries on the "something went wrong with our dimension-traveling device" chart.
* Many colony worlds in the ''[[TabletopGame/{{TwentyThreeHundredAD}} 2300 AD]]'' universe have dextro-based life. To get around this, human colonists sterilize large patches of ground and use "pay dirt" from Earth to set up a localized biosphere suitable for growing crops. On the other hand, many native creatures from dextro-worlds (most infamously [[EverythingIsTryingToKillYou Aurore]]) will take a bite out of humans or their livestock without worrying whether it will make them sick.

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* In ''{{GURPS}} ''TabletopGame/{{GURPS}} Time Travel'', this is one of the entries on the "something went wrong with our dimension-traveling device" chart.
* Many colony worlds in the ''[[TabletopGame/{{TwentyThreeHundredAD}} 2300 AD]]'' ''TabletopGame/TwentyThreeHundredAD'' universe have dextro-based life. To get around this, human colonists sterilize large patches of ground and use "pay dirt" from Earth to set up a localized biosphere suitable for growing crops. On the other hand, many native creatures from dextro-worlds (most infamously [[EverythingIsTryingToKillYou Aurore]]) will take a bite out of humans or their livestock without worrying whether it will make them sick.
1st Jun '16 8:05:19 PM ArtemisPal
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16th Apr '16 2:46:32 PM erforce
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--> -- ''VideoGame/MassEffect2''

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--> -- -->-- ''VideoGame/MassEffect2''



** Referenced darkly in Creator/AlanMoore's ''LeagueOfExtraordinaryGentlemen''; in a text feature in Vol. 2, it is revealed that Alice emerged from the Looking Glass world with her entire body mirror-reversed. As a result, she was unable to eat normal food, and ultimately starved to death.

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** Referenced darkly in Creator/AlanMoore's ''LeagueOfExtraordinaryGentlemen''; ''Comicbook/TheLeagueOfExtraordinaryGentlemen''; in a text feature in Vol. 2, it is revealed that Alice emerged from the Looking Glass world with her entire body mirror-reversed. As a result, she was unable to eat normal food, and ultimately starved to death.
9th Mar '16 1:31:42 PM justanid
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[[folder: Literature ]]

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[[folder: Literature ]]
[[folder:Fan Fiction]]
* In the massively crossover fanfic ''Bring Me the Head of Harry Potter'', it's revealed that Voldemort used a spell that turned people inside out. Examining a battlefield long after the fact, Willow Rosenberg feels the earth's pain from wrong-chirality organic molecule poisoning.
* One ''Series/StargateSG1'' fanfic mentions a right-handed world being used as a prison planet. Plenty of oxygen, but if you escape the prison camp there's absolutely nothing to eat. Unless you [[spoiler: dismember the guards]].
[[/folder]]

[[folder:Literature]]






























* In the massively crossover fanfic ''Bring Me the Head of Harry Potter'', it's revealed that Voldemort used a spell that turned people inside out. Examining a battlefield long after the fact, Willow Rosenberg feels the earth's pain from wrong-chirality organic molecule poisoning.
* One ''Series/StargateSG1'' fanfic mentions a right-handed world being used as a prison planet. Plenty of oxygen, but if you escape the prison camp there's absolutely nothing to eat. Unless you [[spoiler: dismember the guards]].








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