Mutations Flashcards
In a protein, what are amino acids linked by
Peptide bonds to form polypeptide chains
What does the sequence of amino acids determine
The function and structure of the protein
What are proteins held in a 3D shape by
Peptide bonds, hydrogen bonds and interactions between amino acids
Proteins have a large variety of functions (share)
Structural Hormonal Antibodies Receptors Enzymes
What is a mutation
A change in structure or composition of an organism’s genes
Mutagenic agents
Increase the chance of mutations e.g. x-rays, UV light
What can mutations result in
No protein or a faulty protein being produced
What do single gene (point) mutations involve
Alteration of a DNA nucleotide sequence as a result of substitution, insertion or deletion
Examples of single gene mutations
Substitution, insertion, deletion (SID)
Missense
Replacing one amino acid with another
Nonsense
Replacing an amino acid codon with a premature stop codon so no amino acid is made
Splice site mutation
Results in some introns being retained and/or some exons not being included in the mature mRNA
Nucleotide insertions or deletions result in
Frame shift mutations where all codons and therefore amino acids after the mutation are changed
Chromosome mutations include
Translocation, inversion, deletion and duplication (TIDD)
Translocation
a section of a chromosome is added to another chromosome that is not its homologous partner
