Chapter 18 Bio – Flashcards
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The role of a metabolite that controls a repressible operon is to
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bind to the repressor protein and activate it.
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The tryptophan operon is a repressible operon that is
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turned off whenever tryptophan is added to the growth medium.
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Which of the following is a protein produced by a regulatory gene
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repressor
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A lack of which molecule would result in the cell's inability to "turn off" genes
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corepressor
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Which of the following, when taken up by the cell, binds to the repressor so that the repressor no longer binds to the operator?
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inducer
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Most repressor proteins are allosteric. Which of the following binds with the repressor to alter its conformation?
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inducer
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A mutation that inactivates the regulatory gene of a repressible operon in an E. coli cell would result in
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continuous transcription of the structural gene controlled by that regulator.
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The lactose operon is likely to be transcribed when
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the cyclic AMP and lactose levels are both high within the cell.
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Transcription of the structural genes in an inducible operon
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starts when the pathway's substrate is present.
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For a repressible operon to be transcribed, which of the following must occur?
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RNA polymerase must bind to the promoter, and the repressor must be inactive.
