Welcome to the Quiz!
This quiz contains 14 questions from a mix of 1 subtopics.
What are inducible enzymes?
enzymes produced only when their specific substrate is available
enzymes that are produced continuously
enzymes that can be inhibited when not required
enzymes that regulate the expression of other genes
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What are repressible enzymes?
enzymes that can have their production inhibited when not required
enzymes that regulate the expression of other genes
enzymes produced only when their specific substrate is available
enzymes that are produced continuously
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What is an operon?
a type of enzyme
a type of protein
a non-coding region of DNA
a cluster of genes controlled by a single promoter
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What does the lac operon enable Escherichia coli to do?
use lactose as an energy source
use glucose as an energy source
break down proteins
break down fats
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What happens when lactose is absent in the regulation of the lac operon?
the structural genes are transcribed
RNA polymerase can bind to the promoter and initiate transcription
the repressor binds to the operator
the repressor protein changes shape and is released from the operator region
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What happens when lactose is present in the regulation of the lac operon?
RNA polymerase is blocked from the promoter
lactose binds to the repressor protein
the repressor binds to the operator
no transcription of the structural genes occurs
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What is the role of the operator region in an operon?
it encodes proteins that regulate the expression of the structural genes
it is where RNA polymerase binds to initiate transcription
it codes for proteins, typically enzymes
it is a sequence where regulatory proteins can bind
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What is the role of the promoter region in an operon?
it is a sequence where regulatory proteins can bind
it is where RNA polymerase binds to initiate transcription
it encodes proteins that regulate the expression of the structural genes
it codes for proteins, typically enzymes
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What is the function of the lacI regulatory gene of the lac operon?
it produces a repressor protein that controls the operon's activity
it breaks down lactose into glucose and galactose
it transports lactose into the cell
it modifies lactose or its by-products
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What happens when the repressor protein binds to the operator region in the regulation of the lac operon?
the structural genes are transcribed
RNA polymerase can bind to the promoter and initiate transcription
RNA polymerase is blocked from the promoter
the repressor protein changes shape and is released from the operator region
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What happens when lactose binds to the repressor protein in the regulation of the lac operon?
RNA polymerase is blocked from the promoter
the repressor binds to the operator
no transcription of the structural genes occurs
the repressor protein changes shape and is released from the operator region
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What is the function of the structural genes in an operon?
they encode proteins that regulate the expression of the other genes
they code for proteins, typically enzymes
they are a sequence where regulatory proteins can bind
they are the site where RNA polymerase binds to initiate transcription
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What happens when the repressor protein is released from the operator region in the regulation of the lac operon?
no transcription of the structural genes occurs
RNA polymerase is blocked from the promoter
the repressor binds to the operator again
RNA polymerase can bind to the promoter and initiate transcription
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What is the preferred energy source of E. coli?
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