AP Biology Operons

What is the function of the Lac Operon?

• Regulates protein synthesis

• Controls the expression of genes involved in lactose metabolism

• Regulates glucose metabolism

• Controls cell division

Explain how the Trp Operon works.

• The Trp Operon regulates the transcription of genes based on glucose levels

• The Trp Operon functions by responding to changes in oxygen levels

• The Trp Operon works by regulating the transcription of genes involved in tryptophan biosynthesis based on the levels of tryptophan in the cell.

• The Trp Operon is involved in lipid metabolism

Tags

NGSS.HS-LS1-6

Differentiate between Inducible and Repressible Operons.

• Inducible operons are turned on by default and can be turned off by an inducer molecule

• Inducible operons are turned off by default and can be turned on by an inducer molecule, while repressible operons are turned on by default and can be turned off by a corepressor molecule.

• Inducible operons are always active and do not require any external molecules for regulation

• Repressible operons are turned off by default and can be turned on by a corepressor molecule

How is positive control of operons achieved?

• Activator proteins bind to the promoter region of the operon.

• Repressor proteins bind to the promoter region of the operon.

• Activator proteins bind to the coding region of the operon.

• Activator proteins bind to the operator region of the operon.

Describe the mechanism of negative control of operons.

• Inducer binds to operator, preventing transcription

• Corepressor binds to repressor, enhancing its binding to operator

• Activator protein binds to operator, preventing transcription

• Repressor protein binds to operator, preventing transcription; Corepressor or inducer binds to repressor, releasing it from operator.

Why are operons important in gene regulation?

• Operons have no impact on gene regulation

• Operons only regulate one gene at a time

• Operons increase gene expression randomly

• Operons enable efficient regulation of gene expression by coordinating the expression of related genes.

What happens when the lac repressor is bound to the operator in the Lac Operon?

• Translation of the structural genes in the Lac Operon is activated.

• The Lac Operon is shut down completely.

• The Lac Operon becomes hyperactive.

• Transcription of the structural genes in the Lac Operon is repressed.

In the Trp Operon, what happens when tryptophan levels are high?

• Repression of gene transcription

• Enhanced protein synthesis

• Increase in mRNA levels

• Activation of gene transcription

Tags

NGSS.HS-LS1-3

Give an example of an inducible operon.

• trp operon

• lac operon

• gal operon

• tet operon

How do activators play a role in positive control of operons?

• Activators degrade RNA polymerase in the operon.

• Activators have no impact on operon regulation.

• Activators enhance transcription by facilitating RNA polymerase recruitment.

• Activators inhibit transcription by blocking RNA polymerase recruitment.