Here's a breakdown:

* DNA (Deoxyribonucleic Acid): DNA is made up of four different nucleotides:

* Adenine (A)

* Guanine (G)

* Cytosine (C)

* Thymine (T)

* RNA (Ribonucleic Acid): RNA also uses the same nucleotides as DNA except for one difference:

* Uracil (U) replaces Thymine (T)

Each nucleotide consists of three parts:

1. A sugar molecule: This is either deoxyribose (in DNA) or ribose (in RNA).

2. A phosphate group: This provides the backbone structure of the nucleic acid chain.

3. A nitrogenous base: This is one of the four bases mentioned above (A, G, C, T or U).

These nucleotides connect in a chain to form the long strands of DNA and RNA, which then fold and interact to carry genetic information and perform various biological functions.