Like words in a sentence, the DNA sequence of each gene determines the amino acid sequence for the protein it encodes. We can think about DNA gene sequence as a sentence made up entirely of three-letter words. The sun was hot but the old man did not get his hat. This sentence represents a gene. Each letter corresponds to a nucleotide base, and each word represents a codon.
Point mutations are single-base changes in a gene's DNA sequence.
A third type of mutation, called a silent mutation, does not result in an amino acid change. Frameshift mutations result from insertion or deletion of a more than one base into the DNA sequence. Insertions and deletions add or remove chunks of DNA sequence containing many DNA bases. These mutations alter many amino acids in the protein at the same time.