About this Author
DBL%20Hendrix%20small.png College chemistry, 1983

Derek Lowe The 2002 Model

Dbl%20new%20portrait%20B%26W.png After 10 years of blogging. . .

Derek Lowe, an Arkansan by birth, got his BA from Hendrix College and his PhD in organic chemistry from Duke before spending time in Germany on a Humboldt Fellowship on his post-doc. He's worked for several major pharmaceutical companies since 1989 on drug discovery projects against schizophrenia, Alzheimer's, diabetes, osteoporosis and other diseases. To contact Derek email him directly: Twitter: Dereklowe

Chemistry and Drug Data: Drugbank
Chempedia Lab
Synthetic Pages
Organic Chemistry Portal
Not Voodoo

Chemistry and Pharma Blogs:
Org Prep Daily
The Haystack
A New Merck, Reviewed
Liberal Arts Chemistry
Electron Pusher
All Things Metathesis
C&E News Blogs
Chemiotics II
Chemical Space
Noel O'Blog
In Vivo Blog
Terra Sigilatta
BBSRC/Douglas Kell
Realizations in Biostatistics
ChemSpider Blog
Organic Chem - Education & Industry
Pharma Strategy Blog
No Name No Slogan
Practical Fragments
The Curious Wavefunction
Natural Product Man
Fragment Literature
Chemistry World Blog
Synthetic Nature
Chemistry Blog
Synthesizing Ideas
Eye on FDA
Chemical Forums
Symyx Blog
Sceptical Chymist
Lamentations on Chemistry
Computational Organic Chemistry
Mining Drugs
Henry Rzepa

Science Blogs and News:
Bad Science
The Loom
Uncertain Principles
Fierce Biotech
Blogs for Industry
Omics! Omics!
Young Female Scientist
Notional Slurry
Nobel Intent
SciTech Daily
Science Blog
Gene Expression (I)
Gene Expression (II)
Adventures in Ethics and Science
Transterrestrial Musings
Slashdot Science
Cosmic Variance
Biology News Net

Medical Blogs
DB's Medical Rants
Science-Based Medicine
Respectful Insolence
Diabetes Mine

Economics and Business
Marginal Revolution
The Volokh Conspiracy
Knowledge Problem

Politics / Current Events
Virginia Postrel
Belmont Club
Mickey Kaus

Belles Lettres
Uncouth Reflections
Arts and Letters Daily
In the Pipeline: Don't miss Derek Lowe's excellent commentary on drug discovery and the pharma industry in general at In the Pipeline

In the Pipeline

« Lost Arts | Main | Don't Talk To Yourself So Much »

March 31, 2005

Why Carbon Matters

Email This Entry

Posted by Derek

One of my correspondents wrote to ask "What makes carbon so special?" That is, how come all the life we know about is based on it?

There are several qualities that we organic chemists (and living beings) admire about carbon. But before counting the ways, let me start by saying that I'm talking about "life as we know it." As that Steven Benner review article that I spoke about a few weeks ago makes clear, you can imagine chemical domains at other temperatures and pressures that could support life of another kind.

But for the only life we've found so far, the Earthly kind, the temperature and pressure space is roughly bounded by the territory of liquid water. Higher pressures will let it stay liquid up to higher temperatures, and we have organisms that will ride right along with them. Likewise, high ionic strength will let you keep a liquid matrix down to much lower temperatures, and we have that covered here on Earth, too.

Inside this range, carbon has a lot of advantages. It forms very stable bonds to itself, first of all. Forming and breaking them (under controlled conditions!) is one of the major challenges of organic synthesis. Carbon atoms can be strung out to give you virtually any size molecule you want; there seems to be no upper limit and there's no reason to expect one. This is important, because a likely requirement for any kind of chemical-based life is large molecules with structural diversity. Life's bound to be complex, and carbon compounds give you all the complexity you can handle - straight and branched chains, rings, whatever you want.

And those bonds come in more than one flavor. While carbon-carbon single bonds form a 3-D tetrahedral lattice (found in its pure form in diamond), double bonded carbons can all flatten out into the same plane. The best natural example is graphite, made up of flat sheets of tiled carbon rings, full of alternating double and single bonds. The sliding motion of those sheets over each other gives pencil lead its properties. And there are triple-bonded carbons, too, which end up in a straight line. Carbon gives you a wonderful 1D / 2D / 3D building set.

There's another key thing about the element. More structural (and reactive) diversity comes from all the ways that carbon can form bonds with other elements. Oxygen, sulfur, nitrogen, phosphorus and many other elements readily form carbon derivatives under Earthly conditions, and these give you the crazy variety of organic chemistry. We've got solids, liquids, and gases, acids and bases of all strengths, nonpolar compounds and polar ones fitted with all kinds of electron-rich and electron-poor zones, and reactivity all the way from rock-solid to burst-into-flames.

I think that it's much more likely that we'll find life that uses different carbon-based compounds than it is that we find life based on siloxanes or some other framework. Organic chemistry is too useful to avoid. Now, organic chemists are another matter entirely. . .

Comments (2) + TrackBacks (0) | Category: General Scientific News


1. Sam Jaffe on April 1, 2005 10:21 AM writes...

Excellent post. Only 117 more to go!

Permalink to Comment

2. Emeka Okafor on April 2, 2005 11:23 AM writes...

Steve jurevetson's 'Ode to Carbon' provides an interesting perspective to this topic.

Permalink to Comment


Email this entry to:

Your email address:

Message (optional):

The Last Post
The GSK Layoffs Continue, By Proxy
The Move is Nigh
Another Alzheimer's IPO
Cutbacks at C&E News
Sanofi Pays to Get Back Into Oncology
An Irresponsible Statement About Curing Cancer
Oliver Sacks on Turning Back to Chemistry