Here's why:

* Nucleotides are the building blocks of nucleic acids like DNA and RNA.

* ATP has three main components:

* Adenine: A nitrogenous base

* Ribose: A five-carbon sugar

* Triphosphate group: Three phosphate groups attached to the ribose

While ATP is sometimes categorized as a high-energy compound due to its role in cellular energy transfer, its fundamental structure places it firmly within the nucleotide category.