ribóz

Ribóz, also known as ribose, is a simple sugar belonging to the class of aldopentoses. Its chemical formula is C5H10O5. In nature, the biologically important form is D-ribose, which can exist in linear form or cyclize to a furanose ring. In solution, ribose commonly adopts a beta-D-ribofuranose configuration when incorporated into nucleotides.

In biology, ribose is a fundamental component of ribonucleic acid (RNA) where it forms the sugar backbone of ribonucleotides through phosphodiester linkages. Ribose also appears in various essential cofactors and nucleotides, such as adenosine triphosphate (ATP), nicotinamide adenine dinucleotide (NAD+), flavin adenine dinucleotide (FAD), and coenzyme A. In contrast, deoxyribose, lacking the 2' hydroxyl group, is the sugar in deoxyribonucleic acid (DNA). The difference between ribose and deoxyribose is central to the structural and functional distinction between RNA and DNA.

Biosynthesis and metabolism of ribose are closely tied to the pentose phosphate pathway, which generates ribose-5-phosphate for nucleotide synthesis. Ribose-5-phosphate can be converted to phosphoribosyl pyrophosphate (PRPP), a key precursor for nucleotide assembly. Free ribose can also be obtained from nucleic acid turnover or dietary sources, and D-ribose is sold as a dietary supplement, though its clinical benefits vary by condition and are a subject of ongoing research.