RNAProtein160-page14 - Prokaryote Transcription and...

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Gene Expression – DNA to Protein - 14 Rate of Polypeptide Synthesis A polypeptide is generally synthesized in about a minute. However, it is typical of mRNA to be working along many ribosomes at a time to direct the synthesis of many polypeptide molecules in sequence. As soon as the 5' cap of a mRNA leaves one ribosome it will attach to the small subunit of an adjacent ribosome to initiate protein synthesis at that ribosome. It is common for one mRNA to have many ribosomes associated at once. Such complexes are called polyribosomes.
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Unformatted text preview: Prokaryote Transcription and Translation In prokaryotes, both transcription and translation occur in the cytoplasm of the cell. In addition, virtually all the DNA codes for amino acids; bacterial genes lack introns. Consequently, translation can be initiated as soon as the mRNA transcript is long enough to be attached to ribosomes, and several genes can be transcribed in tandem from groups of related genes on the chromosome. Polyribosomes are common in prokaryotes, too....
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This note was uploaded on 12/29/2011 for the course BIO 151 taught by Professor Edwards during the Spring '10 term at SUNY Stony Brook.

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