Ribonucleic acid is a polymer of nucleotide. The ribose-3' of nucleotide and ribose-5' of next nucleotide are bound as phophodiester bonding. There are two kinds of ribonucleic acid, DNA(deoxyribonuleic acid) and RNA(ribonucleic acid). The difference between DNA and RNA is a functional group of ribose-2' of nucleotide.

Ribonucleic acid consists of ribose, nucleobase and phophate.

• Nucleobase

Purine		Pyrimidine
Adenine(A)	Guanine(G)	Cytosine(C)	Thymine(T)	Uracil(U)

5-Methylcytosine	6-Methyladenine

These methyl group does not distub the formation of hydrogen bonding of base-pair.

Oligo-RNA tends to be degraded by base-catalytic hydrolysis in alkaline solution. RNase catalyzes this reaction without cofactors such as metal ions.

• IUPAC Nucleotide Definition