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From: baez@x.ucr.edu (John Baez)
Newsgroups: sci.bio
Subject: Re: Creating life
Message-ID: <2392@ucrmath.UCR.EDU>
Date: 6 Nov 89 23:53:31 GMT
References: <2461@umbc3.UMBC.EDU> <4516@utastro.UUCP> <4782@jane.uh.edu> <1989Nov5.014949.25863@agate.berkeley.edu>
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In article <1989Nov5.014949.25863@agate.berkeley.edu> mkkuhner@codon1.berkeley.edu.UUCP (Mary K. Kuhner) writes:
>
>Would reversing the chirality of the entire organism change
>its chemical properties?  I seem to recall reading that it
>would.  Certainly you would have to reverse every chiral molecule
>
>Mary Kuhner
>mkkuhner@enzyme.berkeley.edu

Stereoisomers (= chirally reversed molecules) have essentially
identical chemical properties except in reaction with other
molecules with handedness.  (I say `essentially' because the
weak (nuclear) force violates parity, but this effect is minute.)
Thus if one created all ones ingredients and working tools
`from scratch', e.g. from molecules which are left-right 
symmetric, one could create a chiral-reversed virus the same
way as a usual one.  If one uses a lot of chiral molecules from
existing organisms in doing DNA research it'd be a lot of trouble
to synthesize reversed versions of everything... can anyone 
more knowledgeable on biochem sketch how much work this'd be?

While on this subject... is there any up-to-date word out on
why the human heart is not left-right symmetric and whether
this assymetry is genetically encoded, and how?? This has 
always fascinated me!