mol gen unit 3

Gene Expression

The process by which information from a gene is used to synthesize proteins or RNAs that affect a phenotype.

Promoter

A DNA sequence where RNA polymerase binds to initiate transcription.

Transcription Factors (TFs)

Proteins that bind to specific DNA sequences to regulate the transcription of genes.

TATA Box

A DNA sequence found in the promoter region of genes that is crucial for the initiation of transcription.

RNA Polymerase II

An enzyme responsible for synthesizing mRNA from DNA during transcription.

Sigma Factor

A protein needed for the initiation of transcription in prokaryotes; it helps RNA polymerase bind to the promoter.

General Transcription Factors (GTFs)

Proteins that are necessary for the transcription of all protein-encoding genes in eukaryotes.

Mediator Complex

A multi-protein complex that acts as a bridge between transcription factors and RNA polymerase.

Phosphorylation

The addition of a phosphate group to a protein or other organic molecule, which can alter its function.

Chromatin Structure

The arrangement of chromatin (DNA and protein) that influences gene expression.

Eukaryotic Transcription Initiation

A complex process that involves multiple proteins and regulatory sequences to initiate transcription.

Enhancers

Regulatory DNA sequences that can increase the likelihood of transcription of particular genes.

Splicing

The process by which introns are removed from pre-mRNA and exons are joined together.

Alternative Splicing

A regulated process that allows a single gene to produce multiple mRNA variants, leading to diverse protein products.

Introns

Non-coding segments of a gene that are removed during RNA processing.

Exons

Coding segments of a gene that are retained during RNA splicing and form the final mRNA.

Ribozyme

An RNA molecule capable of catalyzing specific biochemical reactions, similar to protein enzymes.

Self-Splicing Introns

Introns that can catalyze their own removal without the need for additional proteins or enzymes.

RNA Interference (RNAi)

A biological process in which RNA molecules inhibit gene expression or translation.

Small Interfering RNA (siRNA)

Short, double-stranded RNA molecules that promote the degradation of complementary mRNA.

MicroRNA (miRNA)

Small non-coding RNA molecules that regulate gene expression post-transcriptionally.

Insulators

DNA sequences that can block the interaction between enhancers and promoters.

Lac Operon

A group of genes in E. coli involved in the metabolism of lactose.

Inducible System

A system where gene expression is activated by the presence of an inducer molecule.

Repressible System

A system where gene expression is inhibited by the presence of a repressor molecule.

Combinatorial Control

The regulation of gene expression through multiple signals and factors interacting simultaneously.

CpG Islands

DNA regions rich in cytosine and guanine nucleotides often associated with gene promoters and subject to methylation.

Methylation

The addition of methyl groups to DNA, often affecting gene expression.

Histone Acetylation

The addition of acetyl groups to histones, usually associated with increased gene expression.

Chromatin Remodeling

The dynamic modification of the chromatin structure to allow access to DNA for transcription.

Transcriptional Activators

Proteins that enhance the transcription of specific genes.

Transcriptional Repressors

Proteins that inhibit the transcription of specific genes.

Feedback Loop

A regulatory mechanism where the output of a process influences the operation of the same process in a circular fashion.

Bicoid

A maternal effect gene in Drosophila that regulates anterior-posterior axis development.

Gap Genes

Genes that define broad regions of the embryo during early development.

Pair-Rule Genes

Genes that define segments in the developing embryo and are essential for proper segmentation.

Segmentation Polarity Genes

Genes that maintain the polarity within each segment of the embryo.

Homeotic Genes

Genes that determine the identity of body segments in organisms.

Epigenetics

The study of heritable changes in gene expression that do not involve changes to the underlying DNA sequence.

Gene Imprinting

A form of epigenetic inheritance where certain genes are expressed in a parent-of-origin-specific manner.

Morphogen

A substance that governs the pattern of tissue development in the process of morphogenesis.

Transcriptional Network

A group of genes regulated by a common set of transcription factors.

Cell Differentiation

The process by which a less specialized cell becomes a more specialized cell type.

Induced Pluripotent Stem Cells (iPSCs)

Somatic cells that have been genetically reprogrammed to an embryonic stem-cell-like state.

Differential Gene Expression

The process in which cells with the same genome express different genes, leading to different cell types.

Developmental Biology

The study of the process by which organisms grow and develop.

Transgenic Organism

An organism that has been genetically modified to contain a gene from another species.

CRISPR/Cas9

A revolutionary genome editing technology that allows for precise modifications to DNA.

SRNA

Small RNA molecules that regulate gene expression and function at the post-transcriptional level.

RNA Binding Proteins

Proteins that bind to RNA molecules and can influence RNA stability, localization, and translation.

Chromatin Accessibility

The likelihood that regions of DNA will be accessible for transcription factors and other proteins to bind.

Promoter-Proximal Elements

Regulatory sequences located near the promoter that can influence gene expression.

Enhancer-Promoter Interactions

The physical interaction between enhancer regions and the promoters of genes that they regulate.

Sequence-Specific Binding

The ability of transcription factors to bind to specific DNA sequences to regulate transcription.

Transcription Bubble

The region of unwound DNA around the RNA polymerase during transcription.

Nucleosome

A basic unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound around a core of histone proteins.

Post-Transcriptional Regulation

Control of gene expression at the mRNA stage on the path to protein synthesis.

Transcriptional Integrity

The maintenance of sequence and structure of RNA transcripts to ensure proper gene expression.

Non-Coding RNAs

RNA molecules that are not translated into proteins but can have regulatory functions.

Alternate Promoters

Different promoter regions that can initiate transcription of the same gene under varying conditions.

Transcriptional Bursting

A phenomenon in which gene expression occurs in bursts or rapid cycles rather than continuously.

Functional Genomics

The study of gene functions and interactions within a biological context.

RNA Decay Pathways

Mechanisms by which RNA molecules are degraded, thereby regulating gene expression.

Genomic Imprinting

The process by which certain genes are expressed in a parent-of-origin-specific manner.

Transcriptome

The complete set of transcripts in a cell, including mRNA, non-coding RNA, and small RNA.

Regulatory Networks

Complex networks of gene interactions that control gene expression and cellular function.

Behavioral Epigenetics

The study of how environmental factors influence gene expression and behavior through epigenetic mechanisms.

Transcriptional Reprogramming

The process of altering the expression of genes, often occurring during cellular differentiation or reprogramming.

7SK RNA

A small nuclear RNA that plays a crucial role in RNA polymerase II transcription regulation by inhibiting it.

Histone Code

The hypothesis that specific combinations of histone modifications influence gene expression.

Nerve Growth Factor (NGF)

A neurotrophic factor that promotes the survival and growth of neurons.

Synaptic Plasticity

The ability of synapses to strengthen or weaken over time, important for learning and memory.

Inducible Gene Expression

A gene expression system that can be turned on or off in response to specific signals.

RNA Pol II

RNA polymerase II, the enzyme responsible for transcribing mRNA in eukaryotes.

Poly(A) Tail

A stretch of adenine nucleotides added to the 3' end of an mRNA molecule, important for stability and transport.

Cleavage and Polyadenylation Specificity Factor (CPSF)

A protein involved in the 3' end processing of the pre-mRNA.