Everything about RNA — intro

RNA, Everything about it.

I read and refer Harper's Biochemistry from Lange Publications.
Visit their Website at http://www.lrpub.com

I relied extensively on Lehninger for this article. Solid book, timeless. From Worth Publishers Inc.
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Introduction
Synthesis of an mRNA molecule Part 1
Synthesis of an mRNA molecule Part 2
Termination of mRNA synthesis

Introduction
RNA is a nucleic acid, known to have both informational and catalytic activities. This immediately suggests an intermediate transitory role played by RNA in the evolution of life. Unlike DNA, RNA exists in different forms, each form serving a different purpose. DNA directed RNA synthesis results in the formation of mRNA molecules which translate to give protiens, the functional entities in the cell. tRNA and rRNA are also involved in this process. RNA is the sole genetic(informational) component of many viruses.

Having RNA as the middle step in the flow of information from DNA to protien is convenient and desirable for the cell in many ways. The critical single copy of DNA need not be disturbed for each and every protien that has to be synthesized in the cell. Once transcribred from the parent DNA strand, RNA molecules exhibit a staggering amount of flexibility and versatility. They can be spliced, degraded and passed through polyribosomal complexes many times over.

Lets begin with the synthesis of an mRNA molecule from a DNA template. We shall then move on posttranscrptional modification of the mRNA strand. Many special functions of RNA and exotic types of RNA are encountered in this step. Then we'll take a look at retroviruses and other RNA viruses.