Lecture 7

Question 1

What is a constitutive promoter?

Answer 1

A promoter that is always active, leading to stable gene expression under all circumstances

Question 2

What is an inducible promoter?

Answer 2

A promoter that is activated or deactivated based on a stimulus, which can lead to fluctuations in gene expression

Question 3

What is signal transduction?

Answer 3

The process in which a signal is detected by a sensor and then transmitted to regulatory machinery

Question 4

What is quorum sensing?

Answer 4

The production of small extracellular molecules that accumulate and trigger group behaviors when they reach a threshold concentration

Question 5

What is attenuation?

Answer 5

A transcriptional control mechanism in prokaryotes that prematurely terminates mRNA synthesis

Question 6

How does attenuation work in the tryptophan operon?

Answer 6

When tryptophan is abundant, a leader peptide is synthesized, leading to the formation of a stem-loop structure that terminates transcription. When tryptophan is scarce, the leader peptide is not synthesized, allowing transcription to continue

Question 7

What is the stringent response?

Answer 7

A regulatory mechanism that shuts down macromolecule synthesis and activates survival pathways in response to stress