DNA Repair Mechanisms

This set of flashcards covers key terms and concepts related to DNA repair mechanisms and mutations.

Deletion

A type of mutation where a part of the DNA sequence is missing.

Transition Mutation

A type of point mutation that substitutes one purine for another or one pyrimidine for another.

Open Reading Frame (ORF)

A continuous stretch of codons that has the potential to be translated into a protein.

DNA Repair

The collection of processes by which a cell identifies and corrects damage to its DNA.

MutS Protein

A protein involved in the mismatch repair system that recognizes mismatched base pairs.

MutL Protein

A protein that works with MutS in the mismatch repair pathway to facilitate the repair of DNA.

Excision Repair

A repair process that excises damaged or incorrectly paired nucleotides from the DNA strand.

Base Excision Repair (BER)

A cellular mechanism that repairs damaged DNA throughout the cell cycle.

Nucleotide Excision Repair (NER)

A repair mechanism that removes a wide variety of DNA damage, including bulky adducts.

Homologous Recombination

A type of genetic recombination used to repair double-strand breaks in DNA.

Non-Homologous End Joining (NHEJ)

A pathway that repairs double-strand breaks by directly joining the ends of the broken DNA.

DNA Ligase

An enzyme that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond.

Single-Strand Break Repair

Repair processes that manage breaks occurring in one strand of the DNA double helix.

Translocation

A genetic abnormality where a chromosome piece breaks off and attaches to another chromosome.

Mutagenesis

The process by which the genetic information of an organism is changed, resulting in a mutation.

Point Mutation

A mutation affecting only one or very few nucleotides in a gene sequence.

Photoreactivation

A direct DNA repair mechanism that uses light to repair UV-induced dimers.

DNA Damage Response (DDR)

A set of cellular pathways that respond to DNA damage.

Chromosomal Aberration

A variation from the normal structure or number of chromosomes.

Pigmentosa

A term often related to genetic conditions that can affect pigmentation, such as retinitis pigmentosa.

Mismatch Repair (MMR)

A cellular mechanism for recognizing and correcting incorrect insertions, deletions, and misincorporated bases.

Apurinic Site

A site in DNA that has lost a purine base and can lead to mutations.

Oxidative Stress

An imbalance between the production of free radicals and the body’s ability to counteract their harmful effects.

DNA Polymerase

An enzyme that synthesizes DNA molecules from nucleotides.

Mutagen

An agent that causes mutations in the DNA.

Hydrolysis

A chemical reaction involving the breakdown of a compound due to reaction with water.

Homologous Chromosomes

Chromosome pairs that are similar in shape, size, and genetic content.

Radial Spacing

The organization of chromatin in a radial structure in the nucleus of a cell.

Gene Therapy

An experimental technique that uses genes to treat or prevent disease.

Allele

An alternative form of a gene found at the same place on a chromosome.

Transposable Elements

Segments of DNA that can move around to different spots within the genome.

Eukaryotic DNA Repair Complexes

Multisubunit structures that perform various DNA repair functions in eukaryotic cells.

RNA Interference

A biological process where RNA molecules inhibit gene expression by causing the destruction of specific mRNA molecules.

Karyotype

A visual representation of all the chromosomes in a cell.

Cisplatin

A chemotherapy drug that induces DNA cross-linking and triggers apoptosis.

Adenine Methylation

A modification of adenine bases in DNA that regulates gene expression and DNA repair.

Fidelity of DNA Replication

The accuracy of DNA replication processes to minimize mutations.

Recombination Repair

A DNA repair process that occurs during homologous recombination.

Transcription-Coupled Repair

A DNA repair process that prioritizes repairing damage to the active strands of transcribing DNA.

Genome Integrity

The maintenance of the complete and functional set of genetic information.

Catalytic Activity

The ability of an enzyme to catalyze a biochemical reaction.

Genomic Instability

An increased tendency of the genome to acquire mutations.

DNA Double-Strand Breaks

A severe form of DNA damage where both strands of the DNA helix are broken.

Cell Cycle Checkpoints

Control mechanisms in the cell cycle that ensure proper division.

Enzymatic Repair Mechanisms

Biological processes whereby enzymes correct DNA damage.

Transcription Factors

Proteins that help to initiate or regulate the transcription of a gene.

Cellular Response to DNA Damage

How cells react to various forms of DNA damage.

Phosphorylation

A biochemical process that involves adding a phosphate group to an organic molecule.

Ligase

An enzyme that joins two nucleic acid strands.

Cancer Genetics

The study of genetic mutations that can lead to cancer.

Retinitis Pigmentosa

An inherited degenerative disease that causes vision loss due to retinal degeneration.

Mutational Hotspot

Regions in the genome that are more prone to mutations.