Transcriptional Regulation: Prokaryotes (Session 29)

Flashcards covering key concepts of transcriptional regulation in prokaryotes, including operons, enzymes, and genetic mutations.

Catabolic Enzymes

Enzymes that break down macromolecules and are produced only when a nutrient is present.

Anabolic Enzymes

Enzymes that synthesize macromolecules and are made only when the nutrient is not present.

Operon Theory

The concept that a single signal can regulate the expression of a cluster of genes that are involved in the same process.

Polycistronic mRNA

A type of mRNA that is co-transcribed from a single promoter for multiple genes.

Lac Operon

A model of prokaryotic gene regulation involving genes for β-galactosidase, lac permease, and transacetylase.

Lac Repressor

A protein that binds to the lac operon to block transcription in the absence of lactose.

Transcription Induction

The process of initiating transcription of the lac operon induced by the presence of lactose.

Catabolite Repression

A regulatory mechanism whereby glucose concentration controls the utilization of lactose.

cAMP

Cyclic AMP, a molecule that increases when glucose levels are low and is involved in signaling pathways for gene expression.

CAP Protein

Cyclic AMP receptor protein that binds cAMP and stimulates RNA polymerase binding to the lac promoter.

Cis-acting Elements

DNA sequences that act only on the same DNA molecule.

Trans-acting Factors

Proteins that can act at a distance from their coding sequences and can influence the expression of different DNA molecules.

Genetic Dissection

The process of studying genetic mutations to understand gene function and regulation.

Inducible System (I)

A system that can be activated by an inducer, such as IPTG.

Constitutive System (C)

A system that is expressed continuously regardless of inducers.

Mutation

A change in the DNA sequence that can affect gene function.

DNA Binding Motifs

Specific structural motifs in proteins that enable them to bind to DNA sequences, such as helix-turn-helix structure.