A nucleotide is a basic building block of nucleic acids, which are essential for all living organisms. Each nucleotide consists of three components: a sugar molecule, a phosphate group, and a nitrogenous base. The sequence of nucleotides in a strand of DNA or RNA encodes genetic information, determining the traits and functions of an organism. Nucleotides play a crucial role in cellular processes, including energy transfer and signaling. For example, ATP (adenosine triphosphate) is a nucleotide that serves as the primary energy currency in cells. Additionally, nucleotides are involved in the synthesis of DNA and RNA, which are vital for heredity and protein production.