1. Protein Synthesis and Mutation
Mutation = Permanent, (sometimes) heritable DNA change
Point mutation (base substitutions)
Missense mutation
Nonsense mutation (premature stop)
Silent mutation
Frameshift mutations
Insertions or deletions
Dramatic change in amino acids
Run-ons, premature stops (nonsense mut.)

2. Protein synthesis and mutation
The Creation of Mutation (mutagenesis):
Spontaneous mutation
Occurs in DNA replication (1 in 109 bp)
Polymerase makes mistakes
Chemical mutagens (alcohol, tobacco, drugs)
Increases rate to 1 in ,000)
Radiation
X rays, gamma rays break DNA, bases
UV light causes knots in DNA strand

3. Mutation: Some Definitions
A heritable change in the genetic material
Mutations may be neutral, beneficial, or harmful
Mutagen: Agent that causes mutations
Spontaneous mutations: Occur in the absence of a mutagen

4. Substitutions
ADDING a nucleotide

5. Insertion or deletion Called a “frameshift mutation” – affects CODONS
THEBIGCATATETHERAT = THE BIG CAT ATE THE RAT
THEBIGCBATATETHERAT = THE BIG CBA TAT ETH ERA T

6. Summary: Mutations Substitution mutations-one base pair is changed
FRAMESHIFT:
Insertions (additions)
Deletions
Mutagens-physical and chemical agents that interact DNA to cause mutations—exp.: xrays