Editing Protein primary structure (section)

==Primary structure in other molecules==
{{main|Nucleic acid primary structure}}

Any linear-chain heteropolymer can be said to have a "primary structure" by analogy to the usage of the term for proteins, but this usage is rare compared to the extremely common usage in reference to proteins. In [[RNA]], which also has extensive [[secondary structure]], the linear chain of bases is generally just referred to as the "sequence" as it is in [[DNA]] (which usually forms a linear double helix with little secondary structure). Other biological polymers such as [[polysaccharides]] can also be considered to have a primary structure, although the usage is not standard.