Sunday, June 29, 2008

Spliceosome U1


For an organism to make proteins necessary for life, the genes in DNA are copied to RNA by a protein called RNA polymerase which I showed in a picture and described here previously. Once the mRNA is copied, it needs to be modified or "edited" (the m before RNA stands for messinger, since there are different kinds of RNA) because, for some reason not yet understood, there are unused parts between the usable parts of the gene. There are a group of special molecules which do this work called "spliceosomes." They consist of a combination of RNA and proteins. The pictures here show the beginning of the process and the first spliceosome. The ends labeled exon 1 & 2 are usable parts of the RNA that will remain, while the middle unused part, called the intron, will be removed by the molecules. The picture above is a detail of one on Wikipedia under the heading, minor spliceosome.

The picture on the right is the first spliceosome to find a place on the RNA, called U1. The letters making up the structure (G, U, A, & C) stand for the set of molecules (made of atoms) that make up RNA--guanine, uricil, adenine, and cytosine. You can link to Wikipedia to see guanine or to my post here to see them all (update 2008/08). The U1 unit connects with mRNA and starts the processes needed to remove the intron. These actions are present in life in cells known as eukaryotes, which you can read about in Wikipedia here. They are not in prokaryotes. This means this whole set of metabolic activities would have had to develop by chance, along with many other new processes in the eukaryote, if total materialistic, naturalistic (total-natural) evolution is true.
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Update May 20, 2014: I've put in several places that I've changed from advocating Intelligent Design Theory to Direct Supernatural Creationism. I label totally materialistic, naturalistic explanations as "total-natural" in contrast to supernatural, a word already understood.

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