Monday, November 3, 2008

Q: Outline the differences between prokaryotic control of gene expression with the eukaryotic model

In the prokaryotic model, the regulation of transcription is by the control of operons. However, in the eukaryotic model, it is via the control of transcription factors. In prokaryotes, transcription can occur simultaneously with translation as there is no compartmentalisation by a nucleus. In eukaryotes, after transcription, RNA processing has to occur before translation of the mRNA. Transcription is carried out by 1 type of RNA polymerase in prokaryotes, but it is carried out by 3 different RNA polymerase enzymes in eukaryotes. Enhancers are absent in prokaryotes as promote regions on the DNA are regulated by operators, but in the eukaryotic model, enhancers are present to regulate the initiation of transcription from a promoter.

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