Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uunet!aecom!werner
From: werner@aecom.yu.edu (Craig Werner)
Newsgroups: sci.bio
Subject: Re: Omega-3 fatty acids
Message-ID: <2643@aecom.yu.edu>
Date: 2 Dec 89 04:42:54 GMT
References: <859@wrgate.WR.TEK.COM>
Organization: Albert Einstein Coll. of Med., NY
Lines: 22

In article <859@wrgate.WR.TEK.COM>, dant@mrloog.WR.TEK.COM (Dan Tilque) writes:
> 
> Does anyone know the origin of the name "omega-3 fatty acids"?  Somewhere
> I heard that the name derives from the shape of the molecule.  If that's
> so, is the molecule shaped like three omegas or like an omega and a 3?
> 
	Omega is the last letter of the greek alphabet.  Omega-3 means
that the double bonds (the unsaturation) begin from the third carbon from
the end.  The other major kind is omega-6.  In general, unsaturated bonds
start there and continue every third carbon until they stop. You can also
write instead of omega-3, n-3, but omega-3 sounds catchier.
	Hence arachadonic acid C20:4(n-6) has double bonds at 6,9, 12 and
15  from the end, while the most popular omega-3s are
	EPA (C20:5(n-3), at 3,6,9,12, and 15)
and	DHA (C22:6(n-3), at 3,6,9,12, 15, and 18)


-- 
	        Craig Werner   (future MD/PhD, 4.5 years down, 2.5 to go)
	     werner@aecom.YU.EDU -- Albert Einstein College of Medicine
              (1935-14E Eastchester Rd., Bronx NY 10461, 212-931-2517)
                 "What do you expect? Watermelons are out of season!"


Brought to you by Super Global Mega Corp .com