Genetics Ch.19

BBIO 360

Mutations

Changes in the DNA sequence that can result from different types of alterations.

Point mutation

A mutation that involves a single base pair change in the DNA sequence.

Transiticon

A type of point mutation that involves the same structural mutation, more commonly caused by depurination or transversion.

Transversion

A type of point mutation involving the substitution of a purine base with a pyrimidine base or vice versa.

Deletions/Additions

Mutations that involve the addition or deletion of nucleotides in the DNA sequence.

Silent mutations

Mutations that do not alter the sequence of the polypeptide despite a base substitution.

Missense mutation

A mutation that results in a change in the amino acid sequence due to a base substitution.

Nonsense mutation

A mutation that changes a normal codon into a stop codon.

Frameshift mutations

Mutations that involve the addition or deletion of nucleotides not divisible by 3, causing a shift in the reading frame.

Oxidative stress

Imbalance between Reactive Oxygen Species (ROS) and the ability to detoxify them.

Forward mutation

Mutation that changes the wild-type gene into a new variation.

Reverse mutation

Mutation that changes a mutant gene back to the wild type.

Suppressor mutation

A mutation that reverses the phenotypic effects of another mutation.

Mutation rates

The likelihood of a gene being altered by spontaneous or induced mutations.

Spontaneous mutation

Abnormalities in cellular biological processes caused by new mutations in the DNA.

Induced mutations

Mutations caused by environmental factors like radiation, altering the frequency of mutant genes in a population.

Base modifiers

Enzymes to recognize and repair abnormal bases in the DNA.

BER (Base Excision Repair)

Repair mechanisms that modify the structure of nucleotides

Intercalating Agents

Flat structures pushing into double helix. When replication occurs, daughter has mutations.

NER (Nucleotide Excision Repair)

Repair mechanisms that remove bulky DNA lesions caused by chemicals or radiation.

Base Analogues

Incorporated into daughter strands during DNA replication.

MMR (Mismatch Repair)

Repair mechanisms that recognize and correct mismatched DNA strands.

DSB (Double-strand break repair)

Repair mechanism for breaks in both strands of the DNA caused by radiation, chemical mutagens, or ROS.