Trp Operon (14.1) Flashcards
(12 cards)
How is expression of the trp operon regulated? (2 ways)
Negative regulation (using a co-repressor)
Attenuation
Tryptophan is
an essential amino acid
When tryptophan is present, the trp repressor ____ to the operator sequence
When bound to the operator sequence, the transcription of the trp operon is ______
In this system, tryptophan acts as a _______
The regulation of the trp operon by trpR is an example of _____ gene regulation
binds; inhibited; corepressor; negative
Tryptophan bind to the Trp repressor, and acts as a
co-repressor
Attenuation structure
3 and 4 form
Anti termination structure
2 and 3 form
How many complementary regions that can form stem-loop structures are found on the mRNA encoding the trpL peptide?
Four
When tryptophan levels are high
Transcription terminates
Rho Independent
Promotes the formation of the attenuation structure that acts as a transcription termination sequence for RNA polymerase
regions are 3 and 4
When transcription levels are low
Uncharged tRNA cause the ribosome to stall during synthesis of the trlL peptide. The trp codons allows the anti attenuation structure to form and transcription proceeds
regions are 2 and 3
Positive feedback loop
When the product promotes the expression of creating more of the product
Negative feedback loop
when the product blocks the expression of genes creating more of the product
Regulation of the trp operon by the trp repressor is an example of
negative regulation
