Definitions Mutation – any change in the genetic sequence. Gene alteration – when a change in the genetic code changes the amino acid sequence Silent mutation- when a change in the genetic code doesn’t change the amino acid sequence
Kinds of mutations Point mutation – change in just one nucleotide AAA mutates to AAG Insertion mutation – change in sequence by adding one or more bases. Deletion mutation – change in sequence by taking out one or more bases. Frame shift mutation – the result of an insertion or deletion that moves the codons down and changes all the amino acids
Frame shift mutation example AAG TAG CAT ACT AAT AGC ATA CT_
Mutation Worksheet #1 Original DNA: Amino Acid sequence AGA GCA CTT AAA AGG Amino Acid sequence SER-ARG-GLU-PHE-SER Mutated sequence: AGA GCG CTT AAA AGG Amino Acid sequence: Type of mutation: Point mutation Gene alteration: None
Mutation Worksheet #2 Original DNA: Amino Acid sequence AGA GCA CTT AAA AGG Amino Acid sequence SER-ARG-GLU-PHE-SER Mutated sequence: AGA GCA CTT AAT AGG Amino Acid sequence: SER-ARG-GLU-LEU-SER Type of mutation: Point mutation Gene alteration: yes, but only one a.a.
Mutation Worksheet #3 Original DNA: Amino Acid sequence AGA GCA CTT AAA AGG Amino Acid sequence SER-ARG-GLU-PHE-SER Mutated sequence: AGA CAC TTA AAA GG Amino Acid sequence: SER-VAL-ASP-PHE-___ Type of mutation: deletion; frame shift Gene alteration: yes, frame-shift
Mutation Worksheet #4 Original DNA: Amino Acid sequence AGA GCA CTT AAA AGG Amino Acid sequence SER-ARG-GLU-PHE-SER Mutated sequence: AGA GCA ATC CCG TTC GGG CTT AAA AGG Amino Acid sequence: SER-ARG-STOP Type of mutation: insertion Gene alteration: yes, significant
Mutation Worksheet #5 Original DNA: Amino Acid sequence AGA GCA CTT AAA AGG Amino Acid sequence SER-ARG-GLU-PHE-SER Mutated sequence: AGA GCA AAA AGG Amino Acid sequence: SER-ARG-PHE-SER Type of mutation: deletion Gene alteration: yes, missing an a.a.
6. When a point mutation results in the same amino acid sequence, is it still considered a mutation? Yes because a mutation is a change in the genetic code and it may or may not result in a change in the amino acid sequence. A mutation that doesn’t result in a change in the amino acid sequence is called a silent mutation
Mutation Worksheet # Original DNA: Amino Acid sequence AGA GCA CTT AAA AGG Amino Acid sequence SER-ARG-GLU-PHE-SER Mutated sequence: Amino Acid sequence: Type of mutation: Gene alteration: