Freethought & Rationalism Archive

premjan · 10-06-2004, 10:25 PM

Quote:

Originally Posted by wonkothesane

What the heck are nanobacteria? Lifeforms or just odd looking mineral formations? What's the latest opinion?

Just wondering...

I thought nanoarchaeum was confirmed to be an archaebacterium.

RBH · 10-06-2004, 10:46 PM

Here is a recent New Scientist article on nanobacteria.

RBH

Roland98 · 10-07-2004, 05:03 AM

And here is a previous thread on them.

(edited because I just merged the threads and I don't want a self referring thread to break the internet, Jet Black)

premjan · 10-07-2004, 05:34 AM

Quote:

Originally Posted by Peez

Very interesting, but the reports do seem a little overzealous.On what basis are they being described as "cell-like?"Which suggests that, if alive, they could be structurally more similar to viruses than cells. Note that the phospholipid bilayer of cells is typically about 5 nm thick, so a 30 nm spherical cell would loose 70% of its volume to the phospholipid bilayer, leaving a 20 nm sphere for contents. What could we fit into such a sphere? Here are a few approximate sizes from a quick scan:

water molecule: 0.3 nm
glucose molecule: 1.5 nm
diameter of DNA helix: 2 nm
length of DNA coding for a single very simple protein (50 amino acids): at least 52 nm
protein molecule (insulin): 5 nm
smallest known bacteria: 200 nm
smallest known virus (nothing more than a protein box containing minimal genes): 20 nm

Peez

that comes to approx 40,000 water molecules (if only water were present) inside one of the smaller "cells". is that enough to create a metabolism? I suppose even three or four of the right molecules might be enough for that...

Jet Black · 10-07-2004, 05:36 AM

actually I'm going to merge the threads now, since people just started posting in the old one.

Jet Black [EC] Moderator Extraordainaire

espritch · 10-07-2004, 08:38 PM

Quote:

Which suggests that, if alive, they could be structurally more similar to viruses than cells. Note that the phospholipid bilayer of cells is typically about 5 nm thick, so a 30 nm spherical cell would loose 70% of its volume to the phospholipid bilayer, leaving a 20 nm sphere for contents.

We regard all life on Earth as having a common origin since it all shares so many similarities at the genetic level. However, there is nothing that actually precludes life developing independently more than once. If these things really are alive, they might represent a completely separate life form linage. In that case, you wouldn't necessarily expect their structure and even basic mechanisms to mirror those of life forms we are more familiar with. Their cell walls could be a lot thinner. Maybe we are having a hard time recognizing them as life because our view of what life is has been biases by the kind of life we are familiar with.

It would be interesting if they do turn out to be alive. It might require some serious rewriting of the text books.

wonkothesane · 10-09-2004, 01:44 AM

Quote:

Originally Posted by espritch

We regard all life on Earth as having a common origin since it all shares so many similarities at the genetic level. However, there is nothing that actually precludes life developing independently more than once. If these things really are alive, they might represent a completely separate life form linage. In that case, you wouldn't necessarily expect their structure and even basic mechanisms to mirror those of life forms we are more familiar with. Their cell walls could be a lot thinner. Maybe we are having a hard time recognizing them as life because our view of what life is has been biases by the kind of life we are familiar with.

It would be interesting if they do turn out to be alive. It might require some serious rewriting of the text books.

There was a show on the science channel last week about nanobacteria called "Aliens Among Us" and I assume form the title they were exploring this idea, but sadly, I missed the show...

So far, I would love to believe that nanobacteria *is* life, but I have seen no evidence and it just looks to me like our human capacity for pattern recognition is perhaps fooling us...they *look* like life, and that is all...(like maybe "nanobacteria" are the "Mars Face" of microbiology?)

Of course, I would LOVE to be proven wrong.

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10-06-2004, 10:46 PM	#22
RBH Contributor Join Date: Aug 2002 Location: Ohio Posts: 15,407	Here is a recent New Scientist article on nanobacteria. RBH

10-07-2004, 05:03 AM	#23
Roland98 Contributor Join Date: Apr 2003 Location: Gilead Posts: 11,186	And here is a previous thread on them. (edited because I just merged the threads and I don't want a self referring thread to break the internet, Jet Black)

10-07-2004, 05:36 AM	#25
Jet Black Contributor Join Date: Aug 2003 Location: (GSV) Lasting Damage Posts: 10,734	actually I'm going to merge the threads now, since people just started posting in the old one. Jet Black [EC] Moderator Extraordainaire

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