Week 3 S - Gene Regulation in Prokaryotes

Flashcards on Molecular Genetics: Gene Regulation in Prokaryotes.

Catabolite repression

The inhibition of the metabolism of alternative carbon sources by glucose.

Diauxic growth

The biphasic growth of a microorganism when two sugars are present in the growth medium.

Gene regulation

The control of gene expression, allowing bacteria to adapt and optimize resource use.

Operon model

A cluster of genes transcribed as a single mRNA, controlled by a single promoter and operator.

Negative control

A mechanism where a repressor protein prevents gene expression.

Positive control

A mechanism where an activator protein increases gene expression.

Gene induction

The process of switching on a gene by a signal.

Gene repression

The process of switching off a gene by a signal.

Co-effector

Small molecules that cause induction or repression.

Operon

Multiple genes controlled by one promoter/operator, transcribed as a single transcript.

Lac operon

An operon required for the transport and metabolism of lactose in E. coli.

LacI

The lac repressor protein.

lacZ

The gene that encodes β-galactosidase.

lacY

The gene that encodes permease.

Allolactose

An isomer of lactose and the inducer of the lac operon.

Palindrome (in DNA)

An inverted repeat sequence.

CRP

cAMP Receptor Protein, an activator protein involved in catabolite repression.

cAMP

Cyclic AMP, a signal molecule that responds to glucose levels.

Adenylate cyclase

The enzyme that generates cAMP from ATP.