base

Bases (nucleobases) are heterocyclic purine and pyrimidine analogues found in DNA & RNA: adenine / cytosine / guanine / thymine /uracil /

Nucleosides comprise the RNA bases bound to a ribose sugar molecule – examples are cytidine, uridine, adenosine, guanosine, thymidine and inosine. Deoxyribonucleosides comprise bases bound to a molecule of the sugar deoxyribose.

Nucleotides are nucleosides attached to a phosphate (phosphorylated by specific kinases), and deoxynucleotides are phosphorylated deoxyribonucleosides: AMP / ATP / cAMP / CDP / GDP / GMP / GTP / UDP / UMP /