Mutations Flashcards
What is a point mutation?
The changes affect a single base pairs or a small region
How are point mutations classified?
Based on effect on the protein
What is a silent mutation?
No effect on the protein. The mutated codon still encodes the same AA
What is a missense mutation?
The altered codon encodes a different AA. Can have either little effect or a huge effect depending on what gets changed and what it gets changed into
What is a conservative missense mutation?
The new AA has similar properties to the old one
What is a non-conservative missense mutation?
New AA has different properties than the old one
What is a nonsense mutation?
AA encoding codon is replaced by a stop codon and results in a truncated protein
When would a nonsense mutation not be very severe?
If it was right at the end of the protein and the C-terminus wasn’t needed for function
What is an indel?
Small insertion or deletion that causes frameshift mutations
When would an indel have a less severe phenotype?
If 3 bp were inserted or deleted or if it was right at the end of the protein
What are the 4 types of large scale mutations?
Deletion, insertion, inversion, translocation
What is a deletion? What effect would it have on the phenotype?
Removal of all or part of a gene. Usually a very severe phenotypic effect
What is an insertion? What effect would it have on the phenotype?
Addition of new DNA into a locus. If the insertion was in a coding region can have huge effects
What is an inversion? What effect would it have on the phenotype?
Inversion of a DNA segment that results in all the genes facing the opposite way. If the gene gets split or separated from its promotor it will have a huge effect
What is a translocation? What effect would it have on the phenotype?
A segment of DNA gets cut out and moved to another locus. If the gene gets split or separated from its promotor it will have a huge effect
