Lactose Intolerance
What is the utilization of the inducer?
The inducer binds to the repressor, deactivating it and allowing from transcription.
NOTE: This occurs in inducible gene regulation.
What is the utilization of the corepressor?
The corepressor binds to the repressor, activating it, and therefore blocking transcription.
NOTE: This occurs in repressible gene regulation.
Repressible and inducible.
Does cAMP function in positive or negative gene regulation?
Positive gene regultion.
A series of chemical reactions, beginning with reactants (substrates) and ending with products
Both.
What is required for the trp operon to be active?
Lack of tryptophan in the cell.
What is the prime example of repressible gene regulation?
Trp operon.
What will cAMP bind to in the lac operon?
CAP/CRP
What is a feedback inhibition pathway?
Accumulation preventing more accumulation.
Ex. Function of the trp operon
Which form of negative gene regulation does the lac operon utilize?
Inducible
How does the trp operon demonstrate negative feedback in the regulation of tryptophan synthesis?
As the creation of tryptophan, a corepressor, results in the active state of the trp repressor, resulting in halted transcription, negative gene regulation occurs by halting regulation of the trp operon.
What is the prime example of an activator?
Hint: cAMP binds to this protein
CAP/CRP/catabolite activator protein
How is cAMP affected when there is less glucose in the cell?
The cAMP concentration decreases, inactivating CAP, and thus decreasing transcription.
How do operons help the processes in metabolic pathways?
To ‘coordinately control’ genes, or control genes as a group. This allows for all the enzymes of a metabolic pathway to be synthesized at once, under the same stimuli.
What is the function of cAMP in the lac operon?
cAMP activates the CAP (catabolite activator), which then binds to the lac promoter, therefore simulating gene expression.
What would occur to trp transcription if the trp repressor malfunctioned and no longer could switch to an active state?
If the trp repressor couldn't switch to an active state, continuous transcription of the trp operon would occur, leading to the overproduction of tryptophan even in the presence of tryptophan.
How does glucose affect the positive gene regulation of the lac operon?
Glucose inhibits the production of cAMP, reducing the activity of CAP, and therefore, resulting in positive gene regulation of the lac operon.
What does the cAMP concentration ultimately control?
Transcription.
What are the two kinds of regulation that occur in metabolic pathways?
Positive and negative regulation.