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Bio Prac relating to mutations (1 Viewer)
- Thread starter hs17
- Start date
Eagle Mum
Well-Known Member
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- Nov 9, 2020
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1. Agree with Azure - you may get a codon table to help you determine whether a single nucleotide change results in an amino acid change or not. From the table, they might ask you to interpret what the original amino acid (a.a.) should have been and what a.a. it is replaced with.
2. Also as Azure explains, a point insertion or deletion would cause a frameshift which completely disrupts the protein product (nonsense).
3. Note that if a point mutation produces any one of the following - UAA, UAG or UGA stop triplet codons, the peptide (string of amino acids) stops, so the resultant protein may be too short to function.
4. If the point mutation alters a codon which was originally UGU or UGC, to any other combination, then the absence of the cysteine residues may remove a disulfide bridge, destabilising the expected structure of the final folded protein product (I don’t know if you need to know this or not at high school level).
5. At exon-intron boundaries, a point mutation may either create or destroy a splice site which may produce a protein which has a missing or extra peptide segment, which will often affect function.
2. Also as Azure explains, a point insertion or deletion would cause a frameshift which completely disrupts the protein product (nonsense).
3. Note that if a point mutation produces any one of the following - UAA, UAG or UGA stop triplet codons, the peptide (string of amino acids) stops, so the resultant protein may be too short to function.
4. If the point mutation alters a codon which was originally UGU or UGC, to any other combination, then the absence of the cysteine residues may remove a disulfide bridge, destabilising the expected structure of the final folded protein product (I don’t know if you need to know this or not at high school level).
5. At exon-intron boundaries, a point mutation may either create or destroy a splice site which may produce a protein which has a missing or extra peptide segment, which will often affect function.