Each nucleotide is made up of three parts:

1. Sugar: A five-carbon sugar called deoxyribose.

2. Phosphate group: A molecule containing phosphorus and oxygen.

3. Nitrogenous base: One of four different molecules:

* Adenine (A)

* Guanine (G)

* Cytosine (C)

* Thymine (T)

These nucleotides are linked together to form long chains called polynucleotides. The sequence of the nitrogenous bases along the DNA chain is what carries the genetic code.

Here's a simple analogy: think of DNA as a long ladder. The sugar-phosphate groups form the sides of the ladder, and the nitrogenous bases are the rungs. The sequence of the rungs (bases) is what holds the genetic information.