Exam 14: Gene Regulation in Bacteria

Regulation of gene expression may occur at which of the following levels? Check all that apply.

An enzyme catalyzes a substrate into a final product. When the concentration of the final product is high enough, it binds to a regulatory site on the enzyme. This binding at the regulatory site changes the shape of the enzyme, which prevents it from binding the substrate and prevents formation of more final product. This is an example of a(n) ________.

For these questions, match the following to its appropriate letter. Use each letter only once. A) lacI gene product B) Operator C) Allolactose D) Lac operon E) Trp operon F) Tryptophan -Co-repressor

Which of the following is an example of post translational regulation in prokaryotes?

An activator is present and results in the increase in transcription of the target gene. This is an example of ________.

If CAP could not bind to its CAP site, then what would be the result? Assume lactose is present in each scenario.

The term enzyme adaptation is used to describe an enzyme that appears in a living cell following exposure to a specific substrate.

A gene is inducible and under negative control. Which of the following pairs will allow expression of this gene?

For these questions, match the following to its appropriate letter. Use each letter only once. A) lacI gene product B) Operator C) Allolactose D) Lac operon E) Trp operon F) Tryptophan -Inducible

Antisense RNA does which of the following?

For these questions, match the following to its appropriate letter. Use each letter only once. A) lacI gene product B) Operator C) Allolactose D) Lac operon E) Trp operon F) Tryptophan -Trans-acting element

What stem-loop conformations favor attenuation?

DNA that contains instructions for two or more structural genes produces monocistronic mRNA.

A deletion in an operon removes the promoter. How will that affect the transcript that is produced from the operon?

Repressor proteins are responsible for negative transcriptional regulation.

If a bacteria is placed in an environment that contains both glucose and lactose, the regulation of the lac operon will allow which nutrient to be processed first?

A mutation in the lacI gene prevents the gene product from binding allolactose. What will the expression level of the operon be in the absence of lactose?

In the lac operon, the operator is an example of a trans-effect genetic regulation.

Operons that code for anabolic enzyme systems are typically regulated by inducers.

In the lac operon, the CAP site is located next to the ________. When both lactose and glucose are present, this leads to a rate of transcription that is ________.