Which amino acid shows biggest absorbance at 280 nm?

Tryptophan exhibits anomalous behavior in terms of absorbance at 280 nm primarily due to its unique aromatic side chain, which contains an indole ring. This indole ring structure allows tryptophan to absorb ultraviolet light more effectively than other amino acids. In protein concentration determination, this property of tryptophan, along with tyrosine and to a lesser extent phenylalanine, is exploited to estimate the protein content by measuring absorbance at 280 nm. Tryptophan’s strong absorbance at this wavelength, due to its larger and more complex aromatic structure, makes it a key contributor to the overall absorbance of proteins at 280 nm, thus playing a crucial role in spectrophotometric protein assays. Problem: The anomalous behavior of which amino acid’s absorbance at 280 nm is primarily due to its unique aromatic side chain, useful in protein concentration determination? A) Tyrosine B) Tryptophan C) Phenylalanine D) Histidine
Back to Top