DNA contains the genetic code for all living things in the form of genes. Genes are parts of DNA that code for particular traits and proteins. DNA is made up of nucleotides containing a phosphate, sugar (deoxyribose), and one of four nitrogen bases (adenine, thymine, cytosine, or guanine). The bases pair up on the DNA double helix structure with adenine pairing with thymine and cytosine pairing with guanine. During protein synthesis, genes are transcribed into messenger RNA, which is then translated by ribosomes into proteins through codon-anticodon base pairing between mRNA and transfer RNA.