Which one of the following peak absorption of ultraviolet light by heterocyclic bases (Nitrogen bases)

Options

A. 1500 nm
B. 26 nm
C. 75 nm
D. 260 nm

Answer

D

Explanation

Nucleic acid would be expected to have maximum absorbance at 260 nm. It absorb at this wavelength because of nitrogenous bases A, G, C and T of DNA. In a spectrophotomer a sample is exposed to ultraviolet light at 260 nm and a photodetector measures the light that passes through sample.