What molecules make up DNA?
DNA is made of long strings of nucleotides.
A nucleotide is the monomer of a nucleic acid, which DNA and RNA are.
Each nucleotide contains a sugar group, a phosphate group, and an amine group (the nitrogenous base).
There are four different nitrogenous bases that are present in DNA—adenine, thymine, cytosine, and guanine.
Adenine always is present in the DNA double helix opposite thymine, and cytosine is always opposite guanine.
In DNA, the sugar is deoxyribose and forms the "backbone" of one of the strands with the phosphate groups.