A nucleotide is a fundamental molecule in genetics and molecular biology.
It consists of three key components: a phosphate group, a five-carbon sugar (either deoxyribose in DNA or ribose in RNA), and a nitrogenous base.
The nitrogenous base can be adenine (A), guanine (G), cytosine (C), thymine (T) in DNA, or uracil (U) in RNA.
Nucleotides serve as the building blocks for the construction of DNA and RNA molecules, which are responsible for storing, transmitting, and expressing genetic information in all living organisms.