Mutations Flashcards
(10 cards)
What is an addition mutation?
A nucleotide base is added.
What is an deletion mutation?
A base is removed.
What is a substitution mutation?
A base is swapped for another.
What is an inversion mutation?
A base sequence is reversed.
What is an duplication mutation?
One or more bases are duplicated.
What is a translocation mutation?
A base sequence is moved to a different location either in the same chromosome or to a different chromosome.
What are mutagenic agents?
Substances that increase the rate of gene mutations.
How can a substitution mutation not have an effect on protein structure?
- The genetic code is degenerate meaning that the new base triplet could code for the same amino acid. This means the amino acid sequence won’t change and the positions of the bonds formed won’t alter. This means the tertiary structure of the polypeptides won’t change.
- If the mutation happens in an intron it won’t have an effect on the amino acid sequence.
- If a different amino acid is coded for but the bonds form in the same place. This means the tertiary structure won’t change.
How can addition, deletion, and duplication mutations alter protein structure?
They change the number of bases causing a frameshift where completely new amino acids are coded for. The change in amino acid sequence means that the position of the hydrogen, ionic and disulfide bonds alter. This causes the tertiary structure of the polypeptide to change.
If a gene mutation occurs in a gene that codes for the production factor? What effect could this have on transcription?
The tertiary structure of the transcription factor will change meaning that it will no longer be able to bind to the DNA in the promoter region. This could prevent the transcription of the gene that is stimulated or inhibited by the transcription factor.
