3.3.6. Reactions collapse purine and pyrimidine bases, and shows differences.

Nucleic acid: a biopolymer containing three types of monomer units

• a nitrogenous base (nucleobases), either purine or pyrimidine

• a monosaccharide (aldopentose), either D-ribose or 2-deoxy-D-ribose

• phosphoric acid/phospharyl group

Two types - RNA (Ribonucleic Acid) - DNA (Deoxyribonucleic Acid)

The nitrogen bases in nucleotides consist of two general types:

- purines: adenine (A) and guanine (G)

- pyrimidines: cytosine (C), thymine (T) and Uracil (U)

-in RNA, uracil replaces the base thymine (U pairs with A)