DNA Mutation
A point mutation is a change in the nucleotide sequence of a gene. This can result from an error during replication that is not corrected by the usual repair mechanisms. Under normal circumstances, Adenines and thymines should bind one another as should cytosines and guanines .In a base substition mutations a non-complimentary nucleotide is incporated into the new strand. The resulting altered triplet may code for a different amino acid or even a stop codon. Here we see four codons and their corresponding amino acids. A change within the second triplet results in a change in the amino acids. None of the other amino acids are affected. Insertions and deletions result in frame shift mutations. The insertion of an extra nucleotide not only affects the triplet it is part of but all subsequent triplet thus drastically altering he protein product. The result is similar if the nucleotide is deleted.
