Nucleic acids absorb light strongly in the ultraviolet regio

Nucleic acids absorb light strongly in the ultraviolet region of the spectrum because they have ________ double-bond systems.

Solution

Purines and pyrimidines (nitrogen bases) occuring in DNA are A, G, T and C and \'U\' in RNA absorb light near ultra violet region. These bases can exist in their tautomeric forms due to presence of differing arrangement of hydrogen atoms and double bonds. Presence of the conjugated double bond systems enable the nitrogenous bases to absorb light near UV region.