1. Agenda Songs? Go over transcription/translation jokes simulation
Mutations
Practice Quiz / Review time

2. Mutations

3. Causes of Mutations
Random error in DNA replication or DNA proofreading mechanisms
UV radiation
Some chemicals

4. Types of Mutations Substitutions/Point Mutations Additions/Deletions
One nucleotide switched
Additions/Deletions
Inversions
DNA gets rearranged

5. 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

6. Point Mutations
Can 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

7. Non-sense Point Mutations
Protein is completely altered due to a single substitution in….
The start or stop codon!

8. Frameshift Mutations Additions/deletions change the reading frame
Whole protein is altered and usually destroyed
E.g. Tay-Sachs

9. Mutations Usually 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

10. How Can Mutations Be Beneficial?
New proteins accomplish a new task
Gene duplication
Genes get copied
One copy is “free” to mutate without harming the organism
Allows possibility of new helpful protein and old necessary protein to both be produced