Genetic Code Mutations Mutations are errors in codons caused by changes in nucleotide bases. Some mutations may not have much effect. For example, if the codon GAA becomes the codon GAG, because the genetic code is degenerate, the codon will still code for the amino acid glutamate. Such ineffectual mutations are called silent mutations. Some mutations, however, can have a huge affect on coding for amino acids, which can in turn affect what proteins are produced, which can have a profound effect on cellular and organismal function. The most common mutations occur in two ways: 1) a base substitution, in which one base is substituted for another; 2) an insertion or deletion, in which a base is either incorrectly inserted or deleted from a codon. Base Substitutions Mutations Base substitutions can have a variety of effects. The silent mutation cited above is an example of a base substitution, where the change in nucleotide base has no outward effect. A missense
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This note was uploaded on 01/27/2012 for the course BIOLOGY BSC1005 taught by Professor Rodriguez during the Winter '09 term at Broward College.