nucleotideseither
Nucleotides either are the building blocks of nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Each nucleotide consists of three parts: a phosphate group, a pentose sugar (deoxyribose in DNA, ribose in RNA), and a nitrogenous base. The nitrogenous bases are adenine (A), guanine (G), cytosine (C), and thymine (T) in DNA, while RNA contains uracil (U) instead of thymine. These bases pair specifically: A with T (or U in RNA) and G with C. This complementary base pairing is fundamental to DNA replication and RNA transcription. The sequence of nucleotides in a nucleic acid molecule carries the genetic information of an organism. Nucleotides also play crucial roles in cellular energy transfer, as adenosine triphosphate (ATP), and as signaling molecules. The structure and function of nucleotides are essential for all known forms of life.