Gene Regulation Vocabulary

Flashcards covering key vocabulary related to prokaryotic gene regulation and the lac operon, as well as eukaryotic gene regulation.

β-galactosidase (β-gal)

Encoded by the lacZ gene, it breaks down lactose into glucose and galactose.

Permease

Encoded by the lacY gene, it is a membrane transport protein that helps transport lactose into the cell.

Transacetylase

Encoded by the lacA gene.

Operator

A DNA sequence that serves as a binding site for the repressor protein, controlling whether transcription occurs.

Repressor protein

A protein that binds to the operator sequence and blocks RNA polymerase from transcribing the structural genes.

Inducible enzymes

Enzymes synthesized only when their substrate (inducer) is present.

Allolactose

An inducer molecule that binds to the repressor protein, causing it to detach from the operator and allowing transcription to occur.

cAMP

A signaling molecule whose concentration is inversely related to the level of glucose in the cell; it binds to CAP.

Catabolite Activator Protein (CAP)

A protein that binds to DNA and stimulates transcription; it becomes active when bound to cAMP.

Histone modification

Changes to the structure of chromatin, such as acetylation and methylation, that affect the accessibility of DNA for transcription.

Acetylation

The addition of acetyl groups to histone tails, resulting in less compact chromatin and increased transcription.

Methylation

The addition of methyl groups to histone tails, resulting in more compact chromatin and decreased transcription.