1. Nitrogenous bases: These are organic molecules that contain nitrogen and have a ring structure. They are responsible for the genetic code and include adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U).

2. Pentose sugars: These are five-carbon sugars. There are two types: ribose (found in RNA) and deoxyribose (found in DNA).

3. Phosphate groups: These are negatively charged molecules that link the sugar molecules together to form a backbone for the nucleic acid.

These three components come together to form nucleotides. Nucleotides then connect in a chain to form nucleic acids like DNA and RNA.