MBG 2040 Chapter Notes - Chapter 18: Catabolite Activator Protein, Catabolite Repression, Cyclic Adenosine Monophosphate
9 Mar 2016
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Chapter 18 regulation of gene expression in prokaryotes. A bacterium often finds itself in a changing environment. Genetic regulation in bacteria is primarily focused on adapting the bacterium to its environment (turn on/off certain genes when they are/are not needed) Genes that are not required generally are not expressed unless environmental conditions change in a way that makes their expression useful. Certain gene products (trnas, rrnas, ribosomal proteins, rna polymerase subunits, enzymes catalyzing housekeeping functions) are essential components of almost all living cells. Constitutive genes are those that need to be continuously expressed in most cells. Some gene products are needed for cell growth only under certain environmental conditions (permit the cell to adapt to its environment) Regulatory mechanisms allow the synthesis of these gene products only when they are needed cell doesn"t want to waste energy on things it doesn"t need! Lactose is a disaccharide: enzyme needs to cleave it into glucose and galactose.
