User talk:Robert Tito/carbon in life sub

From Citizendium
< User talk:Robert Tito
Revision as of 17:10, 7 April 2007 by imported>Nancy Sculerati
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

Made these changes:I think it reads better- is it still correct? n

Why does carbon hold the central place in forming living materials? The physical chemistry of the carbon atom renders it avid to form many different type of bonds to other elements, and, even more easily, to bond to itself, with carbon-to-carbon bonds. Not only does carbon react with many other kinds of atoms, but, due to its energy content, carbon is able to form different types of (covalent) bonds. These bonds vary in strength as well as in conformation. The standard, most simple, bond carbon can form is that of a tetraeder, or pyramid. That structure can be found in for instance methane gas, and is basis to the hardness of diamonds. Other type of bonds involve more than one shared electron, and for that reason are called double, and triple bonds, these different bonds constitute three entirely different geometries. That means that if a double bond is reduced to a single bond, for example, that region of the molecule actually changes shape. The avidity for carbon to bond to itself facilitates assembly of long chains and rings of carbon; and small carbon molecules (like sugars, amino acids and nucleotides) easily join into huge macromolecules. Those macromolecules can derive stability from their environment by electrostatic interactions such as hydrogen-bridges, and so do not disassociate so easily.

Because many elements are able to form bonds with carbon, organic macromolecules are capable of containing tremendous banks of information coded in their very structure. Not only can each of the constituents forming these huge molecules be one of several categories of chemicals, but each category contains several species (e.g., for nucleotides: adenine, thymine, guanine, cytosine, uracil). The order of species can be varied, and so there are exponential numbers of possible combinations. The shapes of the bonding orbitals of at least some of the carbon bonds add yet additional levels of information -for example, in double bonds, species can be connected in one of two different planes, called in Organic chemistry cis or trans.