Saul Posted May 7, 2022 Report Share Posted May 7, 2022 Recently, there's been a lot of press about organic compounds found in space rocks. All organic compounds found in living things on Earth that have chirality (i.e., that are such that the mirror image of the molecule cannot be moved onto the original molecule by a distance preserving mapping of 3-space), always show up as the L- (or left) version. This asymmetric chirality of living organic molecules, if I remember correctly, gradually ends when the organism dies -- the L-molecules gradually morph into a mixture that's half D- and half L. https://en.wikipedia.org/wiki/Chirality#Biology A recent article in Science News notes that all of the basic amino acids have been found in space rocks. My question: Have any amino acids from space had more of the left version, right version -- or did they all have L- and D- balanced versions? All of the basic amino acids are chiral. My guess: Amino acids found in space rocks have equal amounts of the D- and L- versions of the amino acids. (Reason: It must have taken a long time for these rocks to hit earth -- and dead organics morph, in time, to equal amounts of D- and L- forms.) So it seems very unlikely to me that life on Earth evolved from organics that hit Earth in space rocks. What do you think? (I think the chirality of living Earth molecules is one of the puzzles of life -- how did this happen, IMO, undoubtedly here on Earth.) -- Saul Quote Link to comment Share on other sites More sharing options...
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