Mutations Flashcards
What is a mutation?
A change in the dna base sequence
How are gene mutations caused?
Spontaneous errors during dna replication (interphase)
What are mutagenic agents?
They increase the likelihood of gene mutations as they damage dna
What is a point mutation?
Only one nucleotide is changed. Usually a substitution
What is a frameshift mutation?
Insertion or deletion of one nucleotide. This changes every codon from the point of mutation so a completely different protein is made
What is nonsense?
The mutation results in one of the 3 stop codons.
What is mis-sense?
Results in a different amino acid sequence being coded for.
E.g. GTC -> GAC
What is silent mutation?
Although it is a different codon, the same amino acid is coded for
What happens in sickle cell anemia?
One base is changed which changes the structure of the protein meaning it polymerises more readily in low oxygen
What is called when one triplet codes for more than one amino acid?
Degenerate code
