Overview of Gene Regulation

Flashcards summarizing key concepts on gene regulation and expression from the lecture notes.

What are the two types of gene expression?

Unregulated (Constitutive) and Regulated.

What is the significance of gene regulation in cellular metabolism?

It ensures that cells produce only necessary proteins, usually regulated by feedback inhibition.

What are operons?

Clusters of genes under the control of a single promoter, allowing coordinated regulation of gene expression.

What are the two well-studied examples of operons in bacteria?

The lac operon (inducible) and the trp operon (repressible).

What is diauxic growth?

The sequential use of two sugars by bacteria, typically glucose followed by lactose.

How does catabolite repression work?

It prevents the use of lactose when glucose is available, ensuring efficient energy use.

What role does cyclic AMP (cAMP) play in gene regulation?

cAMP binds to the catabolite activator protein (CAP), affecting lac operon expression.

What are the key players in transcriptional regulation?

Regulatory Proteins and Effector Molecules.

What function do inducers serve in gene regulation?

Inducers increase transcription by binding to activators or preventing repressors from binding to DNA.

What happens when glucose is present in relation to the lac operon?

It inhibits the operon even if lactose is present, optimizing energy use.

What is the main function of the trp operon?

Biosynthesis of the amino acid tryptophan.

What is attenuation in the context of the trp operon?

It stops transcription prematurely under certain conditions.

How do stem-loop structures affect transcription in the trp operon?

Different structures determine whether transcription continues or terminates based on tryptophan availability.

What is allosteric regulation?

It involves binding a molecule to a site other than the active site, causing a conformational change that affects enzyme activity.

What are riboswitches?

RNA elements that change conformation in response to metabolite binding, regulating gene expression.

Give an example of riboswitch function in bacteria.

In B. subtilis, thiamin pyrophosphate (TPP) levels regulate transcription through a stem-loop structure.