Go to this pHet simulation - Gene Machine lac operon
| Draggable item | arrow_right_alt | Corresponding Item |
|---|---|---|
| arrow_right_alt | transcription "switch" for repressor protein |
| arrow_right_alt | regulatory gene |
| arrow_right_alt | lacZ enzyme (Beta-galactosidase) gene |
| arrow_right_alt | transcription "switch" for lacZ enzyme |
| arrow_right_alt | where repressor protein binds |
| arrow_right_alt | repressor protein |
| arrow_right_alt | lacZ enzyme |
| arrow_right_alt | inducer |
What is the function of the repressor protein? How does it carry out its function?
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?
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?
Item 1
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
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 .
Click on the Lactose Transport tab ... what is the role of the lacY gene?
What would happen if there was a mutation in the lacY gene that created a non-functional protein?
Explain why natural selection would "create" an repressible operon for tryptophan production and an inducible operon for lactose digestion
Why are operons (all of them - inducible and repressible) examples of negative feed back loops/regulation
In your own words, summarize how prokaryotes regulate gene expression using operons
SKIP '25/26 - 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
