Nucleic acid is a generic term for DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). DNA and RNA are biopolymers essential to life, and are composed of four kinds of "nucleotides". Protein, which is an important substance of life, is synthesized according to genetic information coded in DNA. The nucleotides are made of three components of a nucleobase, a five-carbon sugar and a phosphate group.

Five-carbon sugars composing DNA and RNA are 2-deoxyribose and ribose, respectively. The structural difference in these sugars is whether they have hydroxyl group at the 2'-position.

There are four kinds of nucleobase for DNA, adenine (A), cytosine (C), guanine (G), and thymine (T), and AT or GC pairs make double helix structure.
RNA's nucleobases are adenine (A), cytosine (C), guanine (G), and uracil (U) and RNA is single stranded.

RNA is transcribed from DNA in cell nucleus. Part of RNA is transported into cytoplasm, and then translated into amino acid sequence of a protein according to base sequence.

The nucleic acid degradation method follows the steps of (1) hydrolyzing yeast RNA with Nuclease P1 to produce 5'-AMP, 5'-CMP, 5'-GMP and 5'-UMP and (2) separating and refining these 5'-nucleotides using ion-exchange column chromatography. 5'-IMP is converted from 5'-AMP by adenylate deaminase.