Encyclopedia of Astrobiology

2015 Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James (Jim) CleavesII, Daniele L. Pinti, José Cernicharo Quintanilla, Daniel Rouan, Tilman Spohn, Stéphane Tirard, Michel Viso

Ribose

Reference work entry
DOI: https://doi.org/10.1007/978-3-662-44185-5_1373

Definition

Ribose is a five-carbon  monosaccharide with three chiral centers (aldopentose) found in ribonucleic acid (RNA) and several coenzymes (ATP, B 12, NAD(P)H, etc.) with the formula (C 5H 10O 5). Ribose has all the hydroxyl groups on the same side in the Fischer projection. Ribose can exist in two enantiomeric forms, D and L. Biological nucleic acids use the D version. Ribose is the precursor to deoxyribose in biology. In water, ribose exists in equilibrium as furanose, open-chain, and pyranose forms (from left to right in Fig. 1). The pyranose form is predominant (76 %). d-Ribose must be phosphorylated to d-ribose 5-phosphate before it can be used by the cell’s enzymes. Ribokinase catalyzes this reaction. Once phosphorylated, d-ribose-5-phosphate is used for the biosynthesis of the  amino acids tryptophan and histidine and in the pentose phosphate pathway. d-Ribose 5-phosphate is further converted to phosphoribosyl pyrophosphate for the biosynthesis of nucleotides.
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Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Earth–Life Science Institute (ELSI)Tokyo Institute of TechnologyMeguro–kuJapan
  2. 2.Institute for Advanced StudyPrincetonUSA
  3. 3.Blue Marble Space Institute of ScienceWashingtonUSA
  4. 4.Center for Chemical EvolutionGeorgia Institute of TechnologyAtlantaUSA