There are several stages involved in the synthesis process, including transcription and translation.
Regions of the genome, typically called genes, provide instructions for creation of protein molecules, which perform most of the important jobs in cells.
Within cells, a variety of mechanisms determine when a gene is switched on and how active it will be.
Insertion or deletion of a single letter can sometimes cause a frameshift mutation, in which the entire amino acid sequence of the resulting protein is changed.
Sometimes errors during DNA replication can duplicate an entire gene or region of a genome.
Because these insertions and deletions, called indels, can make the protein produced by the gene much shorter or much longer, these errors can have a significant impact.
Indels can have a dramatic effect on the protein's structure and function.
Based in San Diego, John Brennan has been writing about science and the environment since 2006.
His articles have appeared in "Plenty," "San Diego Reader," "Santa Barbara Independent" and "East Bay Monthly." Brennan holds a Bachelor of Science in biology from the University of California, San Diego.
Since the sequence of letters in a gene determines the sequence of amino acids in the protein it encodes, a point mutation can change the amino acid sequence of the resulting protein.
Sometimes a change in the protein's amino acid sequence can have dramatic results.