Here's why:

* Nucleotides are the building blocks of nucleic acids (DNA and RNA). They consist of three main components:

* A nitrogenous base: Adenine (A), guanine (G), cytosine (C), thymine (T) in DNA, and uracil (U) in RNA.

* A five-carbon sugar: Deoxyribose in DNA, ribose in RNA.

* A phosphate group: A molecule containing phosphorus and oxygen.

* Lipids are fats and oils, which are made up of fatty acids and glycerol. They play important roles in energy storage, cell structure, and hormone production, but they are not involved in the structure of nucleotides.