The Lac Operon An inducible operon

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Presentation transcript:

The Lac Operon An inducible operon

The Lac Operon Keep in mind  most prokaryotes will prefer glucose as an energy source When it is not present prokaryotes will look to other sources

Lac Structural Genes Genes that code for enzymes that aid in digestion of lactose! How are these different than Trp operon?

Lac operon Repressor gene codes for an active repressor Remember active repressor binds to operator  no transcription Lactose can bind to this repressor and DEACTIVATE IT Lactose bound to repressor means transcription can be promoted!

Meet cAMP Having an AMP around likely means what? What is ATP broken down into? Having an AMP around likely means what? No Gluclose means less ATP

cAMP le gusta CAP CAP = catabolite activator protein cAMP binds with CAP This complex attaches to CAP binding site next to lac promoter Bends DNA so promoter easier for RNA polymerase to find

Lets sum it up What does cAMP tell the cell? What does an inactive repressor tell the cell

The rest of class Discuss this stuff… In writing Personify these two operons! Share with your classmates

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