nukleotída

A nucleotide is a molecule that serves as the basic building block of nucleic acids, such as DNA and RNA. Each nucleotide consists of three parts: a phosphate group, a five-carbon sugar, and a nitrogenous base. The sugar in DNA is deoxyribose, while in RNA it is ribose. The nitrogenous bases are adenine (A), guanine (G), cytosine (C), and thymine (T) in DNA, and adenine (A), guanine (G), cytosine (C), and uracil (U) in RNA.

Nucleotides are linked together by phosphodiester bonds to form long chains that make up the nucleic acid polymers. The sequence of these bases along the nucleic acid chain carries the genetic information of an organism. DNA, with its double-helix structure, stores this information, while RNA plays various roles in gene expression, including carrying genetic code from DNA to ribosomes for protein synthesis.

Beyond their role in genetic material, nucleotides also have important functions within cells as energy carriers, signaling molecules, and components of coenzymes. Adenosine triphosphate (ATP) is a prime example of a nucleotide that serves as the primary energy currency of the cell. The structure and function of nucleotides are fundamental to understanding molecular biology and genetics.