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Politics : Evolution
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From: Brumar892/22/2007 1:23:48 PM
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Life is composed of chiral molecules - which exist in both right-handed and left-handed forms. All DNA & RNA are exclusively right handed, while amino acids in the proteins are left-handed.

Complex molecules such as DNA and proteins are built by adding one amino acid at a time onto a chain.

In any "primordial soup" amino acids would be produced in equal proportions of right and left-handed forms, so there would be an equal probability at each step of adding either a right or left-handed amino acid.

It's mathematically unlikely that only right-handed nucleotides would be added time after time without a single left-handed one being added. Sooner or later an incorrect, left-handed nucleotide would be added. Ditto for proteins and amino acids. Every time another amino acid would be added to the chain of amino acids that makes up a particular protein, the chances are virtually certain that both right and left-handed amino acids will be added.

Unguided, undirected chemistry would produce DNA and proteins composed of a mixture of right and left-handed building blocks. But this is a big problem. For a living cell to function properly, it is absolutely necessary for it to have the correct three-dimensional structure in its DNA and proteins. The three-dimensional structure is in turn dependent upon proteins built from a pure mixture of left-handed amino acids and DNA built from right-handed nucleotides.

Just another problem for the concept of spontaneous generation. One of very many.

There's also a large number of chicken and egg problems involved in the origin of life.
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