DNA Repair and Mutation

Flashcards covering key vocabulary and concepts related to DNA repair processes, mutations, and their mechanisms.

DNA repair

A multi-step process that corrects errors in DNA structure to ensure integrity of genetic information.

Spontaneous mutations

Mutations that occur naturally during biological processes such as DNA replication.

Induced mutations

Mutations that result from external factors such as environmental agents or mutagens.

Mismatches

Errors that occur when DNA polymerase incorporates the wrong base during replication.

DNA polymerase

An enzyme responsible for synthesizing new DNA strands during replication.

Proofreading

The ability of DNA polymerases to correct errors by removing incorrectly paired nucleotides.

Exonuclease

An enzyme that removes nucleotides from the ends of DNA strands.

Mismatch repair systems

Mechanisms that detect and correct base pair mismatches in newly synthesized DNA.

Methylation

The addition of a methyl group to DNA, which helps distinguish between parental and daughter strands.

Base excision repair

A DNA repair process that removes and replaces damaged or abnormal bases.

Nucleotide excision repair

A DNA repair mechanism that removes damaged segments of DNA and replaces them.

Double-strand breaks

A severe form of DNA damage that can lead to chromosome breakage and is repaired by homologous recombination or nonhomologous end joining.

Homologous recombination

A repair process where damaged DNA is repaired using a homologous sequence as a template.

Nonhomologous end joining

A repair mechanism that directly joins broken ends of DNA without a homologous template.

Rec proteins

Proteins involved in homologous recombination that assist in the repair of double-strand breaks.

Thymine dimers

DNA lesions caused by UV light that can lead to mutations if not repaired.

DNA adenine methyltransferase (Dam)

An enzyme that methylates adenine residues in DNA, playing a role in mismatch repair.