Gene Expression Control in Prokaryotes

These flashcards cover key vocabulary terms and their definitions related to the control of gene expression in prokaryotes.

Regulatory protein

A protein that interacts with other sequences to affect gene transcription or translation.

Inducible operon

An operon that is normally off but can be turned on.

Repressible operon

An operon that is normally on but can be turned off.

Lac operon

A specific operon involved in lactose metabolism, governed by both negative and positive controls.

Transcription

The process of copying a segment of DNA into RNA.

mRNA processing

The modifications made to RNA before it is translated into a protein.

Regulatory gene

A gene that produces a repressor or activator to regulate gene expression.

Cis regulatory element

A DNA sequence that affects the expression of genes it is linked to but is not transcribed.

Trans regulatory element

A DNA-binding protein that affects the transcription of linked sequences.

Allosteric regulation

The regulation of a protein's function through the binding of an effector molecule, causing a shape change.

Catabolite repression

The phenomenon where the presence of glucose inhibits the expression of genes involved in the metabolism of other sugars.

Corepressor

A small molecule that binds and activates a repressor, enabling it to bind to an operator and inhibit transcription.

Positive control

Regulation that stimulates gene expression.

Negative control

Regulation that inhibits gene expression.

Operator

The DNA segment that acts as a switch for the operon by controlling RNA polymerase access to the promoter.