Regulation of Gene Expression

These flashcards cover key terms and concepts related to the regulation of gene expression as outlined in the lecture.

Gene Expression

The process by which information from a gene is used to synthesize a functional gene product, typically a protein.

Constitutive Proteins

Proteins that are required at a constant level across all conditions.

Regulatory Gene

A gene that codes for a protein, often a repressor or activator, that controls the expression of other genes.

Operon

A group of closely linked bacterial genes and regulatory sequences that produce a single mRNA transcript.

Negative Control of Transcription

A regulatory mechanism that stops transcription, often by the action of a repressor binding to an operator.

Induction

A process in which transcription is activated only in the presence of specific substrates.

Cyclic AMP (cAMP)

A regulatory nucleotide derived from nucleic acid precursors, involved in metabolic control systems.

Activator Protein

A protein that enhances the transcription of a gene by binding to a specific site on the DNA.

Diauxic Growth

A biphasic growth pattern exhibited by microorganisms when two sugars are present, utilizing one before the other.

CRP (Cyclic AMP Receptor Protein)

An activator protein that binds to cAMP and regulates transcription of genes in response to glucose levels.

Feedback Inhibition

A regulatory mechanism in which the end product of a reaction inhibits its own production.

Regulon

Multiple operons controlled by the same regulatory protein.

Repression

A mechanism where the presence of a small molecule prevents the transcription of genes, often through a repressor.

Positive Control of Transcription

A regulatory mechanism in which an activator protein promotes transcription.

Structural Genes

Genes that code for proteins and are typically expressed as part of an operon.

Transduction by phage conversion

form of horizontal gene transfer for Vibrio cholerae (origin of cholera toxin)

Transformation

form of horizontal gene transfer for Streptococcus pneumoniae acquisition of capsule

Conjugation

Intro of virulence plasmids in E.coli

Transformation/Conjugation

aquisition of antibiotic resistance in Enterococcus faecalis (gram positive)

negative control by induction

operon control where a sugar serves as an inducer molecule to bind and remove a repressor molecule

negative control by repression

control of operon if presence of amino acid that serves as a corepressor

positive control

control of operon if inducer molecule is bound to activator protein at an activator binding site causing RNA polymerase to be recruited to the promoter