nucleosocides

Nucleosides are organic molecules that serve as the building blocks for nucleic acids, DNA and RNA. A nucleoside is composed of two parts: a nucleobase and a sugar. The nucleobase is a nitrogen-containing heterocyclic compound, and the sugar is typically a five-carbon sugar, either ribose in RNA or deoxyribose in DNA. There are five common nucleobases: adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U). Adenine, guanine, cytosine, and thymine are found in DNA, while adenine, guanine, cytosine, and uracil are found in RNA. The nucleobase is attached to the sugar molecule via a glycosidic bond. For example, adenosine is a nucleoside consisting of adenine attached to a ribose sugar. Similarly, deoxyadenosine is a nucleoside composed of adenine attached to a deoxyribose sugar. Nucleosides play crucial roles in cellular metabolism and are involved in energy transfer, cell signaling, and as precursors for the synthesis of DNA and RNA. They are essential components of life, underpinning the genetic code and its expression.