DNA is a chain of subunits called nucleotides which are composed of deoxyribose, phosphate groups, and a nitrogenous base.
Work Step by Step
Deoxyribose is a five-carbon sugar. The phosphate groups, bonded to deoxyribose, make up the backbone of the DNA molecule. There are four different nitrogenous bases that make up DNA: adenine, guanine, cytosine, and thymine. A deoxyribose molecule, a phosphate group, and one of the four nitrogenous bases make up the subunit called a nucleotide, which are the building blocks of the DNA molecule.