How many atoms in DNA molecule?

[M. DeBacle]

I once calculated that there are as many atoms in a DNA molecule as there
are stars in a galaxy: about 7 billion. I hope that someone here would
give an estimate.

[Louis Hom]

In a typical human cell there are about 3 billion base pairs, divided
among 46 chromosomes (each chromosome is a molecule). So one ssDNA
molecule would be about 3/46 = ca. 0.06 billion or 60 million bases long.
Atoms? I guess 5 for the phosphate, about 20 for the sugar, and then, er,
about 15 atoms in the base (I can't remember offhand). So that would be
about 40*60=2400 million atoms in a single strand of a chromosome (give or
take an order of magnitude <g>)?

I can't comment on the number of stars in the galaxy.
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Lou Hom >K'93
lh...@ocf.berkeley.edu
http://www.ocf.berkeley.edu/~lhom/

[Christopher Michael Jones]

There are more like 200 Billion stars in the Milky Way.
If you are talking about smaller galaxies, dwarf galaxies,
or super huge elliptical galaxies in the center of
super clusters, then you will have a different number
of stars. Similarly, DNA molecules vary in size both
from chromosome to chromosome, and from species to
species (the flu virus has very small DNA molecules,
for example).

M. DeBacle (majo...@domo.net) wrote:
> I once calculated that there are as many atoms in a DNA molecule as there
> are stars in a galaxy: about 7 billion. I hope that someone here would
> give an estimate.

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Chris Jones

My Web Page - "http://www.cs.uoregon.edu/~cjones/web/"

[Paul B.H.]

Quick order of magnitude estimate for the number of stars in the galaxy...
3 units (where one unit = 1/3 the number of stars in the galaxy).

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________________
-pbh
http://www.angelfire.com/ma/nnsbhome
"And there it was...gone"