BIOB11H3 Lecture 10: BIOB11 - Lecture 10
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Sps: figs 12-1, 2, 3, 33, 45, 48. Bacteria prefers glucose as its carbon source; in absence of glucose, it sets in motion pathways that enables it to use alternatives such as lactose: lactose is a disaccharide that is made of galactose and glucose. Bacteria prefer to have glucose; when they don"t, lactose acts as an inducer which is a molecule that regulates gene expression (induction takes place) As soon as the inducer (lactose) is introduced, it causes a spike in the mrna (concerning the enzyme b-galctosidase) in response to the lactose; growth continues and shortly followed by enzyme. After the inducer is eliminated, mrna (concerning the enzyme b-galctosidase) levels quickly drop. An operon consists of a few parts: This pathway is regulated by the repressor protein which can bind to the operator: regulatory gene: encodes a repressor protein that binds to the operator and prevents.