Against my better judgement, I'm replying to something that DNAunion posted. I just had to - this author doesn't know what they're talking about.
quote:
As the structural basis for life, one of carbon's important features is that unlike silicon it can readily engage in the formation of chemical bonds with many other atoms
So can silicon. There's actually a wider range for silicone, because of its D orbital. Or perhaps they're discussing pure silicon, as opposed to silicone? If so, they're confusing themselves - silicon itself can't form long chains, only silicone.
quote:
The various organic functional groups, composed of
I'll give just a few examples from what they list. I'm not going to bother to list even all classes of silicon compounds that contain each; I just want to point out that they exist.
"hydrogen" -> All silanes
"oxygen" -> All silicone
"nitrogen" -> Aminofunctional silicone
"phosphorus" ->
hybrid silicone/phosphate groups"sulfur" -> Sulfur silanes
"and a host of metals" -> Silicon is probably most well known for bonding with a variety of metals, often in very useful forms (such as zeolites), even when it crystalizes.
quote:
Silicon, in contrast, interacts with only a few other atoms
The author clearly knows absolutely nothing about what they're talking about.
quote:
and the large silicon molecules are monotonous compared with the combinatorial universe of organic macromolecules.
Laboratory-manufactured silicone macromolecules are no less diverse than laboratory-manufactured petroleum products. Just as with your petroleum products you get a range of hard materials, soft materials, gels, gasses, and other such products, the same holds true for silicone. Of course, just as with laboratory petroleum products, laboratory silicone products tend to have the same oligomer along the length of the backbone. There's no requirement for this (just as there isn't with carbon), except for ease of mass manufacture.
quote:
The electronic properties of carbon, unlike silicon, readily allow the formation of double or even triple bonds with other atoms.
Carbon based life stores energy in adenosine triphosphate (ATP) and diphosphate (ADP); the energy is in the *phosphate* bonds, not in carbon double and triple bonds. Or perhaps they're talking about a different stage in the process?
quote:
Some carbon-containing compounds, therefore, can be highly polarized and thereby capture "resonance energy" and transform this chemical energy to do work or to produce new chemicals in a catalytic manner.
Polarization? Catalytic functionality? Even natural silicon *crystals* have that one in the bag, let alone your more soluable forms.
The only thing that I can think of that carbon's ready affinity for double bonding gets it is benzene rings. Silicon can still create cyclic forms, just not ones with shared double bonds.
quote:
Finally, it is critical that organic reactions, in contrast to silicon-based reactions, are broadly amenable to aqueous conditions.
This author has obviously never heard of silanols, which are quite common in Earth's oceans.
quote:
The likelihood that life throughout the universe is probably carbon-based is encouraged by the fact that carbon is one of the most abundant of the higher elements.
In planetary crusts, silicon is far, far more common.
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"Illuminant light,
illuminate me."
[This message has been edited by Rei, 11-24-2003]
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