DNA Repair and Mutation

These flashcards cover vocabulary terms related to DNA repair and mutations, including definitions, types of mutations, and mechanisms of DNA repair.

DNA Polymerases

Enzymes that proofread and repair mistakes during DNA replication.

Mismatch Repair

A process that uses proteins to scan for and repair errors in DNA after replication.

Methylation

The addition of methyl groups to DNA, which helps in identifying the template strand in mismatch repair.

Direct Repair

Mechanism that converts altered bases back to normal nucleotides.

Base Excision Repair

Repairs DNA by removing a single damaged base and replacing it with the correct one.

Nucleotide Excision Repair

Removes a span of damaged DNA and resynthesizes it using DNA polymerase.

Non-homologous End-Joining

A repair mechanism that joins broken DNA ends without the need for a homologous template.

Homology Directed Repair

A repair mechanism that uses a sister chromatid as a template to repair DNA breaks.

Somatic Mutations

Mutations occurring in non-reproductive cells, affecting only the organism.

Germ-line Mutations

Mutations that occur in gamete-producing cells and can be inherited by offspring.

Transitions

Mutations that change a purine to another purine, or a pyrimidine to another pyrimidine.

Transversions

Mutations that replace a purine with a pyrimidine or vice versa.

Insertions and Deletions (Indels)

Mutations that involve the addition or removal of one or more nucleotides.

Silent Mutations

Mutations that do not change the amino acid sequence of a protein.

Missense Mutations

Mutations that change one amino acid in a protein sequence.

Nonsense Mutations

Mutations that introduce a premature stop codon in a protein sequence.

Neutral Mutations

Mutations that do not affect the structure or function of proteins.

Loss-of-function Mutations

Mutations that damage protein structure, rendering it nonfunctional.

Gain-of-function Mutations

Mutations that alter protein structure, giving it a new function.

Conditional Mutations

Mutations that only alter protein structure under specific environmental conditions.

Lethal Mutations

Mutations that are fatal to the organism's offspring.

Tautomers

Temporary alternate forms of nucleotides that can affect DNA pairing.

Depurination

The spontaneous loss of a purine base from DNA.

Deamination

The process of losing an amine group from a nucleotide, altering its base.

Mutagens

Substances that induce mutations by altering the nucleotides in DNA.

Free Radicals

Highly reactive molecules that can oxidize bases, causing DNA damage.

Thymine Dimers

Covalent linkages between thymine bases caused by UV radiation, altering DNA structure.

Transposons

Mobile genetic elements that can move within the genome and cause mutations.

Chromosomal Rearrangements

Alterations in chromosome structure that can be caused by transposons.

Nucleotide

The basic building block of DNA and RNA, composed of a base, sugar, and phosphate.

DNA Damage

Any alteration to the DNA structure that can affect its function.

Repair Mechanisms

Various processes through which cells fix DNA damage to maintain genomic integrity.