DNA Function and Gene Regulation- Bio Gr 12: Ch 7

DNA Structure

The arrangement of nucleotides in a double helix shape, crucial for genetic information storage.

Double Helix

The structure of DNA, consisting of two intertwined strands that resemble a twisted ladder.

Nucleic Acids

Biomolecules made up of nucleotides, which include DNA and RNA.

Amino Acids

The building blocks of proteins, determined by the sequence of nucleic acids in DNA.

Genetic Coding

The process by which sequences of nucleotides in DNA are translated into amino acid sequences in proteins.

Archibald Garrod

A British physician who proposed the concept of 'inborn errors of metabolism' in relation to genetic disorders.

Alkaptonuria

A genetic disorder studied by Garrod, characterized by dark urine due to the accumulation of homogentisic acid.

Inborn Errors of Metabolism

Genetic mutations leading to metabolic disorders due to defective enzymes.

Beadle and Tatum's Hypothesis

The 'one gene-one enzyme hypothesis' postulates that each gene encodes a specific enzyme.

Neurospora crassa

A type of bread mold used by Beadle and Tatum to support the 'one gene-one enzyme hypothesis'.

Polypeptide Chain

A linear sequence of amino acids linked by peptide bonds that make up proteins.

Central Dogma of Molecular Biology

The framework describing the flow of genetic information: DNA -> RNA -> Protein.

Messenger RNA (mRNA)

The RNA molecule that carries genetic information from DNA to the ribosome for protein synthesis.

Transfer RNA (tRNA)

The type of RNA that transports specific amino acids to the ribosome during translation.

Ribosomal RNA (rRNA)

The RNA component of ribosomes, essential for protein synthesis.

Codons

Triplets of nucleotides in mRNA that correspond to specific amino acids.

Stop Codons

Codons that signal the termination of protein synthesis.

TATA Box

A DNA sequence found in promoters, crucial for the initiation of transcription.

Translation

The process in which ribosomes synthesize proteins based on the sequence of mRNA.

Spliceosome

A complex of RNA and proteins that facilitates the splicing of pre-mRNA.

Exons

Coding regions of a gene that remain in the mRNA after splicing.

Introns

Non-coding regions of a gene that are removed during mRNA splicing.

Alternative Splicing

A process that allows for the creation of multiple protein variants from a single gene.

Peptidyl Transferase

The enzyme activity of the ribosome that catalyzes the formation of peptide bonds.

Activators

Proteins that bind to specific DNA sequences to enhance transcription.

Repressors

Proteins that bind to DNA and inhibit transcription.

Polysomes

Structures formed by multiple ribosomes translating a single mRNA strand simultaneously.

Operons

Clusters of genes in prokaryotes that are regulated together under a single promoter.

Lac Operon

An inducible operon that regulates the metabolism of lactose in bacteria.

Trp Operon

A repressible operon involved in the biosynthesis of tryptophan.

Post-Translational Modifications

Chemical modifications that occur to proteins after translation, affecting their activity.

Ubiquitin

A small protein that tags other proteins for degradation via the proteasome.

Proteasome

A cellular complex that degrades ubiquitin-tagged proteins.

Cancer Cells

Cells that grow uncontrollably due to mutations in regulatory genes.

Oncogenes

Mutated genes that promote cancerous growth.

Genetic Variation

Differences in DNA sequences among individuals, crucial for evolution.

Point Mutations

Small-scale mutations that affect a single nucleotide, classifiable as missense, nonsense, silent, or frameshift mutations.

Frameshift Mutation

A mutation caused by insertion or deletion of nucleotides that shifts the reading frame.

Large Scale Mutations

Mutations that affect large segments of DNA, including amplifications and deletions.

Spontaneous Mutations

Mutations that occur naturally during DNA replication.

Induced Mutations

Mutations caused by external factors or mutagens such as chemicals or radiation.

Pseudogenes

Non-functional DNA sequences that resemble functional genes.

Retrotransposons

Genetic elements that can move within the genome, influencing gene expression.

RNA Polymerase

The enzyme responsible for synthesizing RNA from a DNA template during transcription.

Post-Transcriptional Modifications

Modifications such as capping and polyadenylation that occur to pre-mRNA before it becomes mRNA.

Alternative Splicing

A process allowing a single gene to produce multiple protein isoforms by including or excluding exons.

Small Nuclear Ribonucleoproteins (snRNPs)

Components of the spliceosome involved in mRNA splicing.

Wobble Hypothesis

The idea that the genetic code allows for flexibility in the pairing of tRNA and mRNA codons.

Gene Regulation

Mechanisms that control the expression of genes, ensuring appropriate timing and levels of gene products.

Transcription Factors

Proteins that help initiate or regulate the transcription of genes.

RNA Interference

Biological process wherein RNA molecules inhibit gene expression or translation.

Ubiquitin-Proteasome Pathway

A major pathway of protein degradation involving tagging with ubiquitin.

Neofunctionalization

The process by which a gene acquires a new function after duplication.

Comparative Genomics

The field of study that compares the genomes of different organisms.

Gene Dosage Effects

Phenotypic effects that result from the number of copies of a given gene.

Telomeres

Repetitive sequences at the ends of chromosomes that protect them from degradation.

Centromeres

Region of a chromosome where sister chromatids are joined together.

Missense Mutation

A point mutation that results in the substitution of one amino acid for another.

Silent Mutation

A mutation that does not change the amino acid sequence of a protein.

Nonsense Mutation

A mutation that creates a premature stop codon in a protein sequence.

Trinucleotide Repeat Expansions

Mutations where a sequence of three nucleotides is repeated, often causing genetic disorders.

Gene Therapy

Treatment that aims to correct or replace faulty genes responsible for disease development.

Immunotherapy

A cancer treatment that harnesses the body's immune system to fight cancer cells.

Chemotherapy

A category of cancer treatment that uses drugs to kill rapidly dividing cells.

Radiation Therapy

The use of high doses of radiation to kill cancer cells and shrink tumors.

Personalized Medicine

Medical care tailored to the specific characteristics of each patient, often based on genetic information.

Gene Editing

Techniques that allow for the addition, removal, or alteration of genetic material at particular locations within the genome.

Polyadenylation

The addition of a poly-A tail to the 3' end of mRNA, enhancing stability and translation.

Capping

The modification of the 5' end of mRNA with a 7-methylguanylate cap, crucial for stability and ribosome recognition.

Exon Junction Complex

A protein complex that forms at the splice junctions of mRNA, aiding in maturation and export.

Multi-Functional Enzymes

Proteins that perform multiple functions within a cell, often linked to their structure.

Protein Folding

The process by which a polypeptide chain folds into its three-dimensional functional form.

Cellular Homeostasis

The ability of a cell to maintain stable internal conditions despite external changes.

MicroRNA (miRNA)

Small RNA molecules that regulate gene expression by targeting specific mRNAs for degradation.

Small Interfering RNA (siRNA)

Short double-stranded RNA molecules that interfere with the expression of specific genes.

Gene Duplication

A process where a gene is copied, leading to multiple copies that may evolve new functions.

Cell Cycle Regulation

Processes controlling the progression of cells through the different phases of the cell cycle.

Transcriptional Activation

The process of increasing the likelihood of transcription of a particular gene.

Chromatin Remodeling

The dynamic modification of the structure of chromatin that allows for access to DNA.

Enzymatic Pathways

Series of chemical reactions within a cell that are catalyzed by enzymes.

Cancer Genomics

Study of the genetic alterations found in cancer cells.

Metabolic Disorders

Disruptions in the normal metabolic processes due to genetic mutations.

Neurodegenerative Disorders

Diseases characterized by the progressive degeneration of the structure and function of the nervous system.

DNA Repair Mechanisms

Processes that identify and correct damage to the DNA molecules.

Chemical Mutagens

Substances that can induce mutations by altering the chemical structure of DNA.

Radiation Mutagens

Forms of energy that can cause mutations through direct damage to DNA.

Genetic Disorders

Disease conditions caused by abnormalities in genes or chromosomes.

Personalized Cancer Therapy

Tailored treatment approaches based on the specific genetic makeup of a patient's cancer.

Eco-Evolutionary Dynamics

Interactions between ecological and evolutionary processes that affect genetic variation.

Cell Signaling Pathways

Series of molecular events by which cells respond to external signals and communicate with each other.

Biological Systems

Complex networks of biologically relevant molecules that interact with one another.