nucleotides
The building blocks of DNA are nucleotides. The important components of the nucleotide are a nitrogenous base, deoxyribose 5-carbon sugar , and a phosphate group Figure 14.5 . The nucleotide is named depending on the nitrogenous base. The nitrogenous base can be a purine such as adenine A and guanine G , or a pyrimidine such as cytosine C and thymine T .