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Lac Operon

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Last updated about 3 hours ago
12 questions
Required
8
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3
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3
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3
12
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8
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2
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3
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3
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5
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5
10
Question 1
1.

Draggable itemarrow_right_altCorresponding Item
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Question 2
2.

What is the function of the repressor protein? How does it carry out its function?

Question 3
3.

Inject 5 lactose molecules into the sim... how does the lactose interact with the repressor protein? How does this interaction regulate the expression of the lacZ gene?

Question 4
4.

How does the lactose interact with the lacZ enzyme (there are really 3 enzymes needed)? What does this interaction supply to the bacterium and then how does it affect its own (lacZ enzyme) activity level?

Question 5
5.
  • Item 1
Question 6
6.
The trp operon is a(n) __________ operon because it's default state is __________. This means the bacterium will __________ until __________. The lac operon is __________ because its default state is __________. This means the bacterium will __________ until __________.
Question 7
7.

Click on the Lactose Transport tab ... what is the role of the lacY gene?

Question 8
8.

What would happen if there was a mutation in the lacY gene that created a non-functional protein?

Question 9
9.

Explain why natural selection would "create" an repressible operon for tryptophan production and an inducible operon for lactose digestion

Question 10
10.

Why are operons (all of them - inducible and repressible) examples of negative feed back loops/regulation

Question 11
11.

In your own words, summarize how prokaryotes regulate gene expression using operons

Question 12
12.

SKIP '25 - Mutation Challenge - modify the simulation to create various mutations listed in this spreadsheet

Make a copy - fill out the chart using the sim - paste the link to your copy of the chart in the answer box

Go to this pHet simulation - Gene Machine lac operon
transcription "switch" for repressor protein
regulatory gene
lacZ enzyme (Beta-galactosidase) gene
transcription "switch" for lacZ enzyme
where repressor protein binds
repressor protein
lacZ enzyme
inducer
Item 2
operon whose default state is "on"
operon whose default state is "off"
operon that typically regulates a catabolic process
operon that typically regulates an anabolic process
the translated repressor's "native state" is active
the translated repressor's "native state" is inactive
an inducer is needed to inactive the repressor
a corepressor is needed to active the repressor
an example of an inducer would be allolactose (lactose)
an example of a corepressor would be tryptophan
inducible operon
repressible operon