- Nitrogenous base: Nucleotides contain a nitrogenous base, which can be either a purine or a pyrimidine. Purines have a double-ringed structure, while pyrimidines have a single-ringed structure. The five main nitrogenous bases found in nucleotides are adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U).

- Pentose sugar: Nucleotides also contain a pentose sugar, which is a five-carbon sugar. The pentose sugars found in nucleotides are ribose and deoxyribose. Ribose is found in RNA nucleotides, while deoxyribose is found in DNA nucleotides.

- Phosphate group: Nucleotides contain a phosphate group attached to the pentose sugar. Phosphate groups have a negative charge, which contributes to the overall negative charge of nucleotides.