Mutations Vocab
Type of mutation that can be passed onto progeny
What is a germ line mutation?
Type of mutation that cannot be passed onto progeny. Only effects the individual organism.
What is a somatic mutation?
Mutating GGU --> GCU
Specifically this changes this amino acid for _____.
What is a neutral mutation?
What is glycine for alanine? (both have small & hydrophobic R groups)
Based on using the Ames test, if a new ingredient in a shampoo is found to be a mutagen, what else can the scientist predict?
What is that the ingredient is 90% sure also a carcinogen?
A base that has been modified is removed, next the nucleotide is replaced. Requires DNA glycosylases.
What is BER (base excision repair)?
The addition or removal of a single or a few nucleotides
What are indels?
Adding or removing nucleotides in a multiple of 1 or 2 causes these
What is a frameshift mutation?
Mutating GGU --> UGU
Specifically this changes this amino acid for _____.
What is a missense mutation?
What is glycine for cysteine?
Mechanism of action for ethidium bromide (EtBr)
Once a distortion in the DNA is detected, the 2 DNA strands are separated & held apart by SSBs. The sugar-phosphate backbone is cleaved on both sides of the distortion & helicase removes the damaged region. DNA Polymerase & DNA ligase repair the empty region.
What is NER (nucleotide excision repair)?
A single nucleotide is changed for a different nucleotide
What is a base substitution mutation?
Adding or removing nucleotides in a multiple of 3 causes these
What is an in-frame mutation?
Mutation in which the phenotype is only seen at a particular temperature (i.e. high temperature)
What is a conditional mutation? ("temperature sensitive mutation")
Chemical that commonly causes TA --> CG & CG -->TA transitions by adding a chemical group.
What are alkylating agents?
How mismatch repair functions.
What is restoring nucleotides to their correct structures? The mismatch repair complex brings the incorrect base (new strand) close to the mark for the old strand (methylation in prokaryotes). Exonucleases remove nucleotides from the incorrect base (mismatch) up to the methylation mark. DNA Pol & DNA ligase fix this region.
If this substitution occurred: T--> G
What is a transversion?
If this substitution occurred: T--> C
What is a transition?
Mutation that occurs in a different gene than the original one and acts to hide or suppress the original mutation.
What is an intergenic supressor mutation?
Converts cysteine --> hydroxylaminoacysteine
Converts guanine --> 8-oxy-7,8-dihydrodeoxyguanine
What is hydroxylamine?
What are oxidative radicals?
Used to fix O6-methylguanine & other products of chemical or spontaneous mutation. Does not cut the nucleotides.
What is direct repair?
The number of copies of a short repeat sequence (i.e. CAG) increases over time.
Causes this genetic phenomenon.
What is an expanding nucleotide repeat?
What is anticipation?
Mutating GGU --> GGG
Specifically this changes this amino acid for _____.
What is a silent mutation?
What is glycine for glycine (no change in amino acid).
Mutation that occurs in the same gene as the original one and acts to hide or suppress the original mutation.
What is an intragenic suppressor mutation?
DNA polymerases cannot tell these chemicals apart from the standard nucleotides
What are base analogs?
These general steps are used by all 4 of the main DNA repair pathways (not recombination). List the 4 steps in order.
Enzymes these pathways have in common.
1.Detection
2.Excision
3.Polymerization
4.Ligation
What are DNA polymerase & DNA ligase?