Friday, August 29, 2008

DNA Polymerase


In the picture of DNA replication from August 19, we skip to the left a few molecules along the top and find DNA polymerase. This is the molecule which is necessary for copies of genes (DNA) to be made. DNA replicates in order to produce the next generation of organisms and, in plants and animals, for cell reproduction. We are talking now about Archaea and Cyanobacteria since they were among the first organisms on Earth. The DNA polymerase (pronounced po-LIM-er-ace) has a complex job and we will not go into all the details. I want to show you the pictures of those from a species of Archaea and Cyanobacteria. At the top is a computer structure from Swiss Model RepositoryDNA polymerase from Archea. Details are reported at Uniprot P26811. It has 882 amino acids.

The Cyanobacteria DNA polymerase pictured above has 928 amino acids as reported at Uniprot Q2JWV2. It is shaped in a way that it can work on the DNA molecule to manipulate the chemical reactions needed. It is made by other molecules which can carry out reactions that copy the DNA genes and transform the code of the DNA to proteins. One of those molecules is RNA polymerase, which is pictured in the right column of the blog.

I could go on with showing you the rest of the molecules that are pictured on the DNA replication picture as well as some which are not. There are sub-units of DNA polymerase which repair DNA when it is broken. There are some which attach short molecules at first that have to be replaced later for the DNA replication to be complete. I think, however, that by now you see the vast complexity of even the very first organisms.

There is much to be said about this complexity and I will discuss implications in posts to come. I want to link you to some articles from mainstream scientific journals that help us see that this complexity is a very significant obstacle to the notion of random, materialistic origin of life and total random, materialistic evolution (total-natural evolution) to explain all life.

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