mass of bacteria

Nicholas Landau njl2q at virginia.edu
Tue Apr 9 23:10:28 EST 2002

Wait a minute... what coccus is 0.2 nm in diameter?!?!?!

Maybe a *really tiny* coccus could be 0.2 um in diameter, but 0.2 nm...?

No way Jose.  I don't believe it.  That has got to be off by three orders of
magnitude.  Name the coccus.

Larry Farrell wrote:

> Again, as posted yesterday, some of the smallest cocci are 0.2 nm in diameter and
> smallpox virus is 0.2-0.3 nm x 0.25 nm.
>
> Nicholas Landau wrote:
>
> > The largest viruses are bigger than bacteria?  Which virus?  I never heard
> > that (but then, I never studied virology).
> >
> > --Nick
> >
> > Graham Shepherd wrote:
> >
> > > Smarty <smartman at comcast.net> wrote in message
> > > news:3cab7bd6.18969629 at news.in.comcast.giganews.com...
> > > > Less than 500 milligrams
> > > >
> > >
> > > An unusually unhelpful response.
> > >
> > > You can get an approximation by calculating the volume of the organism from
> > > typical dimensions (eg for E.coli assume it's a cylinder 1 micron long with
> > > a diameter of 0.5 micron) and assume that the density is the same as water.
> > > (It is greater, otherwise you couldn't spin them down - but it's probably
> > > not much greater. You could determine the density on a gradient if it's
> > > critical).
> > >
> > > A rough calculation indicates that the volume is about 0.2 cubic microns.
> > > That's 5,000,000,000 per cubic millimeter, or 5,000,000,000,000 per cubic
> > > cm. Assuming 1 gram per cubic cm, one bacterium weighs about 0.2 picogram.
> > >
> > > Viruses are much more variable in size than bacteria (the biggest viruses
> > > are bigger than the smallest bacteria). But you could do the same
> > > calculation for a specific virus.
> > >
> > > GS
>
> --
> Larry D. Farrell, Ph.D.
> Professor of Microbiology
> Idaho State University