GEN-3000 Chapter Notes - Chapter 15: Lac Operon, Beta-Galactosidase, Operon
30 Nov 2017
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Document Summary
The product of lactose metabolism creates an energy source. When lactose is present it binds to the repressor and the repressor detaches from the operon. Transcription occurs and the products produced are used to break down/assist in the metabolic pathway of lactose. Galactose eventually gets turned into glucose as well. Essential for lactose to serve as energy source in glycolysis. Speculated to be involved in removal of toxic by products of lactose digestion. When lactose is present: transcription is turned on. When lactose is absent: transcription is turned off. Remember: glucose is end game for glycolysis and lactose metabolism. The cell will use glucose before it attempts to metabolize any other sugar. Glucose is present which means the cell will not expend the energy to metabolize lactose when glucose is present and ready for use. Catabolite activating protein (cap): a molecule that activates the expression of lac operon. Cap helps rna polymerase bind easier to the operon.
