1. Nitrogenous Base: These are the building blocks that contain nitrogen and are responsible for the unique coding of each nucleic acid. There are five main types: Adenine (A), Guanine (G), Cytosine (C), Thymine (T) found in DNA, and Uracil (U) found in RNA.

2. Sugar: This is a five-carbon sugar molecule that provides the structural backbone of the nucleic acid. In DNA, the sugar is deoxyribose, while in RNA, the sugar is ribose.

3. Phosphate Group: This negatively charged group is attached to the sugar molecule and links adjacent nucleotides together to form the long chains that make up nucleic acids.

These three parts come together to form a nucleotide. Many nucleotides are then linked together to form a long chain called a polynucleotide, which is what makes up DNA and RNA.