RNA Links the Information in DNA to the Sequence of Amino Acids in Protein

RNA Links the Information in DNA to the Sequence of Amino Acids in Protein

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RNA Links the Information in DNA to the Sequence of Amino Acids in Protein Ribonucleic acid (RNA) was discovered after DNA. DNA, with exceptions in chloroplasts and mitochondria, is restricted to the nucleus (in eukaryotes, the nucleoid region in prokaryotes). RNA occurs in the nucleus as well as in the cytoplasm (also remember that it occurs as part of the ribosomes that line the rough endoplasmic reticulum). Scientists for some time had suspected such a link between DNA and proteins. Cells of developing embryos contain high levels of RNA. Rapidly growing E. coli has half its mass as ribosomes. Ribosomes are 2/3 RNA (a type of RNA known as ribosomal RNA or rRNA) and 1/3 protein. RNA is synthesized from viral DNA in an infected cell before protein synthesis begins. Some viruses, for example Tobacco Mosaic Virus
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Unformatted text preview: (TMV) have RNA in place of DNA. If RNA extracted from a virus was injected into a host cell the cell began to make new viruses. Clearly RNA was involved in protein synthesis. Crick's central dogma. Information flow (with the exception of reverse transcription ) is from DNA to RNA via the process of transcription , and thence to protein via translation . Transcription is the making of an RNA molecule off a DNA template. Translation is the construction of an amino acid sequence (polypeptide) from an RNA molecule. Although originally called dogma, this idea has been tested repeatedly with almost no exceptions to the rule being found (save retroviruses )....
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This note was uploaded on 11/29/2011 for the course BIO BSC1010 taught by Professor Gwenhauner during the Fall '10 term at Broward College.

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