Here's a breakdown:

* DNA (Deoxyribonucleic acid): DNA is made up of two long chains of nucleotides twisted into a double helix. Each nucleotide consists of a deoxyribose sugar, a phosphate group, and one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), or thymine (T).

* RNA (Ribonucleic acid): RNA is also made of nucleotides, but it has a single chain structure. It uses ribose sugar instead of deoxyribose and has uracil (U) instead of thymine.

* ATP (Adenosine triphosphate): ATP is a single nucleotide consisting of adenine, ribose sugar, and three phosphate groups. It's the primary energy currency of cells.

Let me know if you'd like more detail on any of these!