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15 Cards in this Set
- Front
- Back
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Who discovered the Lac Operon |
Francois Jacob Jacques Monod |
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The two scientist was the first to discover a __________ |
Transcriptionally regulated system |
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What does the Lac Operon consist of |
The Lac Operon consists of a polycistronic structural gene regulated by a common promoter and regulatory genes |
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Give some examples similar to a prawns and Where are such arangements common |
Examples of Lac Operon Trp operon Ara operon His operon Val Operon Such arrangements are common in bacteria |
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What are the parts of a Lac Operon |
The Lac Operon consists of 1 regulatory gene that is the I gene which codes for the repressor and 3 structural genes Z- beta galactosidase Y - permease A - transacetylase |
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What is the function of Beta galactosidase |
Is responsible for the hydrolysis of the disaccharide ride into with monomeric units galactose and glucose |
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What is the function of permease |
It increases permeability of the cell to beta galactosides |
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All the 3 gene products in Lac Operon are required for............ |
Metabolism of lactose |
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Name the substrate for the enzyme beta galactosidase and what is its function |
Lactose it regulates switching on and off of the operon and is also called as inducer |
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How is the Lac Operon initiated |
In the absence of a preferred carbon source such as glucose in the growth medium if lactose is provided it is transported into the cells through the actions of permease( a very low level of expression of Lac Operon has to be present in the cell all the time otherwise lactose cannot enter the cell) and induce the operon |
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What is the repressor of the Operon synthesized from |
The I gene |
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What does the repressor do |
It binds to the operator region of the operon and prevents the RNA polymerase from transcribing the operon |
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What happens to the repressor in the presence of a inducing substrate |
It is rendered inactive The RNA polymerase can reach the promoter site and transcribe the operon to hydrolyse lactose of allolactose |
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Regulation of the lac operon by the repressor is called ______ |
Negative feedback, inducible mechanism |
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What is the structure of the lac operon in repressed condition |
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