LAC OPERON - Danielle, Claire, Sakina & Jeremy
Beta-Galactosidase – the enzyme responsible for breaking down lactose, a disaccharide,
into 2 monomer sugars.
Gene Regulation – an overall term for controlling which proteins are produced in the
cell and in the case of enzymes overall metabolic rate. Regulation of genes can occur at 4
levels: transcriptional, post transcriptional, translational, and post translational.
Negative Control System – blocks a particular activity in the cell in this case the Lacl
protein binds to the promoter region and does not allow RNA polymerase to function,
thus the Lac Operon genes are not transcribed.
Operon – a segment of DNA containing adjacent genes including structural genes, an
operator gene and a regulatory gene.
Operator – a short sequence of bases (coding region).
Inducer – a signal molecule which allows the lacl protein to be removed from the
promoter region.
OTHER REFERENCES:
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See pages 255 – 256
http://www.sumanasinc.com/webcontent/animations/content/lacoperon.html
http://www.youtube.com/watch?v=iPQZXMKZEfw&feature=related