Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!sunybcs!boulder!pell
From: pell@boulder.Colorado.EDU (Anthony Pelletier)
Newsgroups: sci.bio
Subject: Re: Chromosome Topology of the Human Genome
Message-ID: <5553@boulder.Colorado.EDU>
Date: 31 Dec 88 20:39:26 GMT
References: <17231@dhw68k.cts.com> <23046@beta.lanl.gov> <2084@aecom.YU.EDU> <11465@reed.UUCP>
Sender: news@boulder.Colorado.EDU
Reply-To: pell@boulder.Colorado.EDU (Anthony Pelletier)
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Organization: University of Colorado, Boulder
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Someone writes:
>> > There is a problem in a chapter of the original Lehninger Biochemistry

(great book, but a bit out-dated, wouldn't you say?)

>> > text that will give you the flavor of the problem.  Leaving *lots* of
>> > other problems aside, the DNA in a human cell if a single straight
>> > strand would just about make it to the moon (if I am recalling the
>> > problem correctly).  

Craig werner writes:
>> 	The DNA from a single cell can be measured in centimeters.  The
>> DNA from a single human being (all told) would probably make it to the
>> moon.

In article <11465@reed.UUCP> alexis@reed.UUCP (Alexis Dimitriadis) writes:

>It's been a few years, but I think it was thus: If you have a strand of
>silk from here to the moon, how do you pack it in a cylinder X by Y mm?
>There was a note to the effect that human DNA and the chromosome have the
>same proportions as the length/width of the strand and the cylinder.
>
>This does seems to square with Craig's estimate of a few cm. length for DNA.
>(I have the book at home, if it's worth the trouble to someone).
>
>Alexis Dimitriadis

Alexis:

God, I hate this...But Craig is quite right (just kidding old boy).
Take a typical animal cell (not salamander), it will have about
3x10^^9nucleotides in it
That would be about one meter of DNA (which is easily measured in centimeters,
I might add).  
(source :Alberts, Bray, Lewis, Raff, Roberts et al. pp.103, if you don't
want to take my word for it).
A useful algorithm, for those who like such things:

1micron of DNA= 2kilodaltons = 3 kilobases (If I remember the old 1,2,3 rule
correctly--I have to look it up everytime I have to teach it to someone).

As for the silk analogy, perhaps they were doing things to scale?
That is, if you increased the diameter of DNA to that of silk, the
comparable length would reach to the moon?  Offhand, this does not sound
right either.  My guess is you just don't know what you are talking about.
Before you make claims like that, you really should check some reputable
reference.  This sort of discussion is just silly, chromsomes stretching
to the moon!!!  This is not a place for the unsupported oppinions
of those who get all there biology from Nova (and misunderstand it at that).

-tony