Each nucleotide is composed of three parts:

* A sugar molecule: This is deoxyribose in DNA.

* A phosphate group: This is the acidic part of the nucleotide.

* A nitrogenous base: This is the part that carries the genetic information. There are four different nitrogenous bases in DNA: adenine (A), guanine (G), cytosine (C), and thymine (T).

The nucleotides are linked together in a chain, forming the DNA molecule. The sequence of the nitrogenous bases along the chain is what makes up the genetic code.