Jun 18, 2014
Substitution Mutations
The replacement of a nucleotide with another that has a different base
Nonsense Mutation -
The formation of one of the three stop codons which marks the end of the polypeptide chain
Effects: This means that the polypeptide is stopped prematurely and the final protein will be shorter and cannot (normally) perform its usual function
Mis-sense Mutation -
Base change results in a different amino acid
Effects: The significance of the change depends on the role of the amino acid.
The 3D shape may change and the protein may be mishapen as a result and therefore unable to perform its function (enzyme)
Silent Mutation -
Triplet code still codes for the same amino acid
Effect: None. The polypeptide is still identical to the original