Regulation of Bacterial Gene Expression

A set of vocabulary flashcards covering key concepts related to bacterial gene regulation and eukaryotic gene expression.

Constitutive Genes

Genes that are expressed at a fixed rate, 'always on'.

Adaptive Genes

Genes that are expressed only as needed.

Inducible Genes

Genes whose expression is triggered by a chemical signal.

Repressible Genes

Genes whose expression is inhibited by the abundance of the end product.

Negative Gene Regulation

Gene regulation where operons are switched off by the active repressor.

Inducible Enzymes

Enzymes that function in catabolic pathways, synthesized upon induction.

Repressible Enzymes

Enzymes that function in anabolic pathways, repressed by end product levels.

trp Operon

An operon involved in tryptophan synthesis, subject to negative control.

lac Operon

An operon that regulates lactose metabolism in bacteria.

Activator Proteins

Proteins that stimulate gene expression by aiding RNA polymerase.

RNA Polymerase

Enzyme that synthesizes RNA from a DNA template.

Cyclic AMP (cAMP)

A small molecule that acts as a signaling molecule to regulate gene expression.

CRP (catabolite activator protein)

An activator that enhances transcription of the lac operon when glucose is low.

Lactose Repressor (LacI)

Protein that represses the lac operon in the absence of lactose.

Allolactose

A byproduct of lactose that acts as an inducer of the lac operon.

Chromatin Structure

The arrangement of chromatin, which affects gene expression.

Histone Acetylation

The addition of acetyl groups to histones, promoting transcription.

DNA Methylation

The addition of methyl groups to DNA bases, often leading to decreased transcription.

Epigenetic Inheritance

Inheritance of traits that do not involve changes to the DNA sequence.

Alternative RNA Splicing

A process that modifies RNA to produce different proteins from the same gene.

MicroRNA (miRNA)

Small RNA molecules that regulate gene expression by binding mRNA.

Small Interfering RNA (siRNA)

RNA molecules that inhibit gene expression through RNA interference.

Transcription Factors

Proteins that bind to DNA to regulate transcription.

Enhancers

Regulatory elements that increase the likelihood of transcription.

Mediator Proteins

Proteins that facilitate interactions between activators and transcription machinery.

Differential Gene Expression

The variation in gene expression among cells with the same genome.

Ubiquitin

A small protein that tags proteins for degradation.

Proteasomes

Complexes that degrade and recycle tagged proteins.

Noncoding RNA (ncRNA)

RNA molecules that do not code for proteins but play regulatory roles.

Heterochromatin

Tightly packed chromatin that is generally inactive in transcription.

Euchromatin

Loosely packed chromatin that is active in gene transcription.

Subunits of RNA Polymerase II

Proteins that make up the enzyme RNA polymerase II involved in transcription.

Regulatory Mechanisms

Various controls that operate at different stages of gene expression.

Promoter Region

A DNA sequence that initiates transcription of a particular gene.

Control Elements

Segments of noncoding DNA that regulate gene transcription by binding transcription factors.

Paternal Alleles

Alleles inherited from the father that can be regulated by methylation.

Maternal Alleles

Alleles inherited from the mother that can be affected by genomic imprinting.

Lactose Permease

The cell surface transporter that allows lactose entry into the cell.

Beta-Galactosidase

Enzyme that breaks down lactose into galactose and glucose.

Mediators of mRNA Stability

Sequences in the UTR that influence the lifespan of mRNAs.

Translational Regulation

Control of gene expression at the stage of protein synthesis.

Histone Methylation

The addition of methyl groups to histones that typically represses transcription.

CRISPR-Cas9 System

A bacterial defense system that uses small ncRNAs to target foreign genetic material.

Gene Mutations

Changes in the genetic code that can affect gene function.