The - not turned off completely just turned down. When it...

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The overall objective in prokaryotes is maximal growth rate when the environment is favorable (i.e. supply of nutrients is adequate). To economize, many genes are only transcribed when the gene product is needed but are turned off when the product is not needed (energy is not wasted on the synthesis of many unnecessary mRNAs and proteins). Of course vital genes are always transcribed. Usually the synthesis of an mRNA is
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Unformatted text preview: not turned off completely just turned down. When it is called "off" it usually means low. Two general categories of regulation Negative control : repressor protein present which prevents transcription, inducer (usually a small molecule) is needed to allow initiation of transcription. Positive control : activator protein induces transcription. No repressor must be overriden....
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This document was uploaded on 11/03/2011 for the course BIOLOGY MCB2010 at Broward College.

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