Every nucleotide is built from a phosphate group, a nitrogenous base and:

1. A nucleotide has exactly three components. 2. Two of them are the phosphate group and the nitrogenous base. 3. The third is a five-carbon sugar, that is a pentose. 4. In DNA that pentose is deoxyribose and in RNA it is ribose. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 3 'Biological Macromolecules', sections 3.1-3.5_