Chapter 11: Gene Expression Regulation in Bacteria

Flashcards covering key vocabulary and concepts from Chapter 11 on gene expression regulation in bacteria.

Gene expression

The process where information flows from DNA to RNA to protein.

Operon

A functional DNA unit in which several related genes are under the control of one promoter.

Polycistronic mRNA

An mRNA molecule that contains multiple genes and is produced from operons.

Inducible operons

Operons that are turned OFF by default but can be turned ON by an inducer molecule.

Repressible operons

Operons that are turned ON by default but can be turned OFF by a corepressor molecule.

Housekeeping genes

Genes required for basic cellular maintenance and everyday living that are always ON.

Transcriptional regulation

The control of gene expression at the transcription stage, most common and efficient point of regulation.

Attenuation

A regulatory mechanism where transcription is started but terminated early based on environmental signals.

Allosteric site

The site on a regulatory protein where small molecules bind to influence its shape and function.

Lac operon

An inducible operon that allows bacteria to metabolize lactose.

Trp operon

A repressible operon involved in the biosynthesis of tryptophan.

Corepressor

A molecule that binds to repressor proteins and enables them to bind to the operator, turning the operon OFF.

Activator proteins

Proteins that bind to DNA and increase the transcription of target genes.

cAMP (Cyclic AMP)

An allosteric effector molecule for CAP that enhances transcription in the lac operon.

Repressor proteins

Proteins that bind to DNA and inhibit transcription, acting as negative control.

Feedback inhibition

A regulatory mechanism where the end product of a pathway inhibits an earlier step in the pathway.

E. coli

A common bacterium often used as a model organism in genetic studies, particularly in operon research.

Catabolic processes

Metabolic processes that involve the breakdown of molecules for energy, often regulated by inducible operons.

Anabolic processes

Metabolic processes that involve the synthesis of molecules, often regulated by repressible operons.

Enzyme adaptation

The phenomenon where enzyme production occurs in response to the presence of their substrates, such as lactose.