Download Chapter 18: Control of Gene Expression in Bacteria

Chapter 18: Control of Gene Expression in Bacteria
Text Vocabulary:
Gene Expression
Transcriptional Control
Translational Control
Post-translational Control
Constitutively
Inducer
Mutagens
Replica Plating
Medium
Constitutive Mutants
Negative Control
Repressor
Positive Control
Activator
Operon
Lac operon
Operator
Allosteric Regulation
Ara operon
AraC
Global gene regulation
Regulon
Lecture 30 “Negative Control of Gene Expression in Bacteria” PPT Review
1.) What category of macromolecules would lactose fall under? Based on the double ring structure
of lactose, how would it further be classified under this macromolecule family?
2.) What is the function of the proteins Galactoside permease and β-Galactosidase?
3.) What is an operon?
4.) What are the genes encoded by the lac operon promoter? Is lacI transcribed from the same lac
operon promoter? Which genes express β-Galactosidase and Galactoside permease?
5.) What is an Operator in terms of prokaryotic operons? Based on its function, what would the
operator be classified as?
6.) What is the function of the protein expressed from LacI? When it interacts, what part does it
interact with on its target and what structure of the protein allows this?
7.) The protein coded by the LacI gene can be altered in a way that changes its function. What is the
name of this change and what induces the change to this protein?
8.) Is the lac operon an example of positive or negative control? Based on the mechanism, explain
why. How can this type of control then be suppressed? (Explain the difference between lactose
being present and absent)
9.) How does glucose affect the transcription of the lac operon? Why? What is it interacting with to
cause the effect?
Lecture 31 “Positive Control of Gene Expression in Bacteria” PPT Review
1.) What are all the components of the DNA comprising the ara operon?
2.) How does the araC act as a regulatory protein in the presence and absence of arabinose?
3.) Slide 9 question: “The bacteria glow in response to a molecule that regulates expression of
genes involved in light-producing chemical reactions. The regulator controls production of the
genes’ mRNA. Therefore, the light-producing genes are under ____ “
4.) Explain the LuxR regulation occurring on Slide 11.
5.) Slide 12 question: LuxR is allosterically regulated by the signaling inducer molecule secreted by
V. fischeri. What does it mean that LuxR is allosterically regulated?
6.) What is a regulon? What is the benefit of regulon for bacterial survival? How are they different
from operons?
7.) How does Vibrio cholera respond to quorum sensing in the human gut?
8.) Slide 16 question: “Why might quorum sensing be beneficial to pathogenic bacteria?”