Types of Mutation Flashcards
3 different types of substitution mutation?
miss-sense
non-sense
silent
What is miss-sense mutation?
Formation of codon that codes for a different
amino acid. PPC differs by 1 amino acid.
What does a miss-sense mutation cause?
The protein which this polypeptide is a part may differ in shape (tertiary structure) and not function properly. For example if it is an enzyme its active site may change shape and no longer be complementary to the substrate and catalyze the reaction.
Example of a miss-sense mutation?
Sickle cell anemia
What is a substitution mutation?
Type of mutation in which a nucleotide in a DNA sequence is replaced by another nucleotide that has a different base.
What is a Silent mutation?
The formation of a different codon but one that codes for the same amino acid as DNA code is degenerate. Mutation has no effect on amino acid produced.
What is a non-sense mutation?
Formation of one of the three stop codons that mark the end of a PPC.
What does a non-sense mutation cause?
The production of the PPC coded for by the section of DNA is stopped prematurely. Final protein is often significantly different and cannot perform its usual function.
What is a Deletion mutation?
The loss of a single nucleotide from a section of DNA.
What does a deletion mutation cause?
The loss of a nucleotide causes a FRAME-SHIFT to the left. All codons before deletion remain unaffected but most triplet codes (codons) after will be different (not all as DNA is degenerate) and lead to the production of a non functional protein. Will considerably alter the phenotype.
What is an addition mutation?
An extra base/nucleotide becomes inserted in the DNA sequence.
What does an addition mutation cause?
Similar effect to deletion mutation except FRAME-SHIFT is to the right. If three (or any multiple of three) bases is added then there will not be a frame-shift. The resulting PPC will be different from the one produced by a normal gene, but not to same extent as frame-shift.
Explain Duplication mutation?
One or more bases are repeated. This produces FRAME-SHIFT to the right.
Explain Inversion mutation?
Group of bases become separated from the DNA sequence and rejoin at the same position but in the inverse order. The base sequence of this portion is therefore reversed and affects amino acid sequence that results.
What is a Translocation mutation?
Group of bases become separated from DNA sequence on one chromosome and become inserted on DNA sequence of a different chromosome.
