deossiribosio

Deossiribosio, also known as deoxyribose or 2'-deoxyribose, is a five-carbon aldose sugar with the molecular formula C5H10O4. It is the sugar component of deoxyribonucleic acid (DNA) and differs from ribose by the absence of an oxygen atom at the 2' position.

Chemically, deoxyribose occurs primarily in the beta-D-2'-deoxyribofuranose form when incorporated into nucleotides. In this form, the 2' carbon carries only a hydrogen atom instead of a hydroxyl group, while the 3' and 5' positions bear hydroxyl groups that participate in phosphodiester bond formation during DNA polymerization. The sugar is covalently attached to a nucleobase at the 1' carbon, forming a deoxynucleoside, and then to one or more phosphate groups to make a deoxynucleotide.

Biologically, deoxyribose is a key structural element of DNA. The sugar-phosphate backbone provides the framework that holds the nucleobases in sequence, enabling genetic information to be stored, replicated, and transcribed. The absence of the 2'-hydroxyl group in DNA increases chemical stability relative to RNA, reducing susceptibility to alkaline hydrolysis and contributing to the enduring nature of the genetic material in many organisms.

Biosynthesis and metabolism center on ribonucleotide reductase, which reduces ribonucleotides to deoxyribonucleotides for DNA synthesis and repair. Deoxyribose also appears as a free metabolite in small amounts but is predominantly encountered in the context of nucleotides and nucleic acids. See also ribose and nucleic acids.