DNA Damage, Repair, and Mutation

These flashcards cover key vocabulary terms and concepts related to DNA damage, repair mechanisms, and mutations as discussed in the lecture notes.

Point Mutation

An alteration of a single (or a few) base-pair(s) of DNA.

Base Substitution

A type of mutation where one base pair in the DNA sequence is replaced with another.

Transition Mutation

A type of base substitution where a purine is replaced by another purine, or a pyrimidine is replaced by another pyrimidine.

Transversion Mutation

A type of base substitution where a purine is replaced by a pyrimidine or vice versa.

INDEL

Insertion or deletion of one or more base pairs in the DNA sequence.

Silent Mutation

A mutation that does not cause a change to the corresponding amino acid.

Conservative Missense Mutation

A mutation that results in a change to a chemically similar amino acid.

Nonconservative Missense Mutation

A mutation that results in a change to a chemically dissimilar amino acid.

Nonsense Mutation

A mutation that changes a codon to a stop codon, terminating protein synthesis.

Frameshift Mutation

A mutation caused by insertions or deletions that shifts the reading frame of the sequence.

Depurination

The loss of a purine base (adenine or guanine) from DNA.

Deamination

The loss of an amine group from a nucleotide, potentially leading to mispairing.

Oxidative Damage

DNA damage caused by reactive oxygen species, which can lead to mutations.

Base Analogs

Chemical compounds that are similar in structure to normal nitrogenous bases and can mispair during DNA replication.

Intercalating Agents

Planar molecules that insert between nitrogen bases in DNA, potentially leading to insertions and deletions.

Pyrimidine Dimers

Covalent bonds formed between adjacent pyrimidines in DNA, often due to UV light exposure, causing replication issues.

Mismatch Repair

Repair mechanism that identifies and corrects mismatches in DNA after replication.

Homologous Recombination

A DNA repair process that uses a homologous sequence as a template for accurate repair of broken DNA strands.

Nonhomologous End Joining

An error-prone repair mechanism for double-strand breaks that does not require a homologous template.

The Ames Test

A test used to assess if chemical compounds have mutagenic properties.