What classification applies to the amino acid Tyrosine?

Tyrosine is classified as an aromatic amino acid due to its structure, which features a phenolic side chain. The presence of a benzene ring with a hydroxyl group (-OH) attached to it is characteristic of aromatic compounds. This structure contributes to its unique chemical properties, including its ability to absorb ultraviolet light, which is often utilized to estimate protein concentration in biochemical assays.

In addition to being aromatic, tyrosine is also polar due to the hydroxyl group, which can form hydrogen bonds with water and other polar substances. However, its classification primarily as an aromatic amino acid is due to the predominant presence of the aromatic ring in its structure. The other classifications, while they may describe some properties of tyrosine, do not specifically encapsulate the fundamental classification of the amino acid itself as well as "aromatic" does.