Mutations Flashcards
What are mutations
Changes in the DNA that can result in no protein or an altered protein being synthesised
What are the 3 types of single gene mutations
- substitution
- insertion
- deletion
Definition of a substitution mutation
Base(s) are switched resulting in missense or nonsense
Describe missense mutations
One amino acid has been changed for another.
What can a missense mutation result it
May result in a non functional protein or little to no effect on the protein
What disease is caused from a missense mutation
PKU
Describe a nonsense mutation
The change in code created a premature stop codon
What does a nonsense mutation result in
A shorter protein
Describe splice-site mutations
Results in some introns being retained and/or some exons not being included in the mature transcript
What are insertion and deletion mutations known as
Frameshift mutations
What’s the definition of an insertion mutation
Base is added in. Will shift the reading frame & all amino acids ‘downstream’
What’s the definition of a deletion mutation
Base is deleted. Will shift the reading frame & all amino acids ‘downstream’
Why are frame shift mutations worse than substation mutations
Beacuse everything is moved so all the amino acids after mutation is changed having major effect on the structure of the protein produced
What are the 4 types of chromosomal mutations
- deletion
- duplication
- translocation
- inversion
Definition of a deletion (chromosomal) mutation
Section of chromosome removed & rest re-joined if needed
