mutations
DESCRIPTION
Mutations. Causes of Mutations. Random error in DNA replication or DNA proofreading mechanisms UV radiation Some chemicals. Types of Mutations. Substitutions/Point Mutations One nucleotide switched Additions/Deletions Inversions DNA gets rearranged. THE FAT CAT ATE THE DOG. - PowerPoint PPT PresentationTRANSCRIPT
Mutations
Causes of Mutations
Random error in DNA replication or DNA proofreading mechanisms
UV radiation
Some chemicals
Types of Mutations
Substitutions/Point Mutations
One nucleotide switched
Additions/Deletions
Inversions DNA gets rearranged
THE FAT CAT ATE THE DOG
Minor substitution/silent mutation:THE FAT CAT ATE THA DOG
Major substitution:THE FAT CAT ATE THE HOG
Addition:THE GFA TCA TAT ETH EHO G
Deletion:THF ATC ATA TET HEH OG
Inversion:THE FAT DOG ATE THE CAT or THE FAH EDT CAT ATE TOG
Point MutationsCan be silent since sometimes multiple codons code for the same amino acid
Can have a minor affect on protein shape/function
Can have a major effect on protein shape/function
Non-sense Point Mutations
Protein is completely altered due to a single substitution in….
The start or stop codon!
Frameshift Mutations
Additions/deletions change the reading frame
Whole protein is altered and usually destroyed
E.g. Tay-Sachs
MutationsUsually neutral (99% of DNA is non-coding)
If they have an effect, usually bad
Very, very rarely the mutation might be beneficial
Source of diversity
How Can Mutations Be Beneficial?
New proteins accomplish a new task
Gene duplicationGenes get copiedOne copy is “free” to mutate without harming the organismAllows possibility of new helpful protein and old necessary protein to both be produced
