Question

Protein concentration can be estimated by measuring the absorbance of protein-containing solutons using UV light. Give the names of the three aminio acids responsible for this and the UV wavelength at which they absorb light. What are some restrictions in using this technique?

Answer 1

The name of the three amino acids responsible for absorbing UV rays are tryptophan, tyrosine and cysteine.

The UV wavelength at which they absorb light is 280 nm.

Restrictions:

(1) The technique is applicable to organic compounds with functional groups containing valence electrons of low excitation energy.

(2) High concentration of analyte alters the refractive index of the solution and that alters the absorbance. For this reason, concentration should be optimal.