# Ribose > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Ribose > Markdown URL: https://mediated.wiki/source/Ribose.md > Source: https://en.wikipedia.org/wiki/Ribose > Source revision: 1342354259 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Group of simple sugar and carbohydrate compounds}} {{Use dmy dates|date=March 2020}} {{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 412792499 | Name = {{nowrap | {{sm|d}}-Ribose}} | ImageFileL1 = D-Ribose.png | ImageFileR1 = DRibose_Fischer.svg | ImageClassL1 = skin-invert-image | ImageClassR1 = skin-invert-image | ImageSizeR1 = 70px | ImageFileL2 = Beta-D-Ribofuranose.svg | ImageFileR2 = Beta-D-Ribopyranose.svg | ImageClassL2 = skin-invert-image | ImageClassR2 = skin-invert-image | IUPACName = D-Ribose
{{sm|d}}-''ribo''-Pentose{{cite web | url=https://iupac.qmul.ac.uk/2carb/app.html | title=Appendix }} | OtherNames = {{nowrap | {{sm|d}}-Ribose}} | SystematicName = (2''R'',3''R'',4''S'',5''R'')-5-(hydroxymethyl)oxolane-2,3,4-triol | Section1 = {{Chembox Identifiers | CASNo = 50-69-1 | CASNo_Ref = {{cascite|correct|CAS}} | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 681HV46001 | EC_number = 200-059-4 | DrugBank_Ref = {{drugbankcite|changed|drugbank}} | DrugBank = DB01936 | PubChem = 5779 | ChEMBL_Ref = {{ebicite|changed|EBI}} | ChEMBL = 1159662 | PubChem2 = 5311110 | PubChem2_Comment = aldehydo form D-(−)-Ribose | ChemSpiderID2_Ref = {{chemspidercite|changed|chemspider}} | ChemSpiderID2 = 4470639 | ChemSpiderID2_Comment = aldehydo form D-(−)-Ribose | SMILES2 = C([C@H]([C@H]([C@H](C=O)O)O)O)O | SMILES2_Comment = aldehydo form D-(−)-Ribose | InChI2 = 1/C5H10O5/c6-1-3(8)5(10)4(9)2-7/h1,3-5,7-10H,2H2/t3-,4+,5-/m0/s1 | InChI2_Comment = aldehydo form D-(−)-Ribose | InChIKey2 = PYMYPHUHKUWMLA-LMVFSUKVBD | InChI3 = 1S/C5H10O5/c6-1-3(8)5(10)4(9)2-7/h1,3-5,7-10H,2H2/t3-,4+,5-/m0/s1 | InChI3_Comment = Aldehydo form D-(−)-Ribose | InChIKey3 = PYMYPHUHKUWMLA-LMVFSUKVSA-N }} | Section2 = {{Chembox Properties | Properties_ref = {{Merck11th|8205}}{{RubberBible62nd|page=C-506}} | Formula = C5H10O5 | MolarMass = 150.13 | MolarMassUnit = g/mol | Appearance = White solid | Density = | MeltingPtC = 95 | Solubility = 100{{nbsp}}g/L (25 °C, 77 °F) | SpecRotation = −21.5° (H2O) }} | Section7 = {{Chembox Hazards | FlashPt = }} | Section8 = {{Chembox Related | OtherFunction = [Arabinose](/source/Arabinose)
[Xylose](/source/Xylose)
[Lyxose](/source/Lyxose) | OtherFunction_label = [aldopentoses](/source/Pentose) | OtherCompounds = [Deoxyribose](/source/Deoxyribose) }} }} alt=|thumb|class=skin-invert-image|{{nowrap | L-Ribose}} Fischer Projection '''Ribose''' is a [simple sugar](/source/simple_sugar) and [carbohydrate](/source/carbohydrate) with [molecular formula](/source/molecular_formula) C5H10O5 and the linear-form composition H−(C=O)−(CHOH)4−H. The naturally occurring form, {{nowrap | '''{{sm|d}}-ribose'''}}, is a component of the [ribonucleotide](/source/ribonucleotide)s from which [RNA](/source/RNA) is built, and so this compound is necessary for [coding](/source/Genetic_code), [decoding](/source/Translation_(biology)), [regulation](/source/Regulatory_RNA) and [expression](/source/RNA_splicing) of [gene](/source/gene)s. It has a [structural analog](/source/structural_analog), [deoxyribose](/source/deoxyribose), which is a similarly essential component of [DNA](/source/DNA). {{nowrap | '''{{sm|l}}-ribose'''}} is an unnatural sugar that was first prepared by [Emil Fischer](/source/Emil_Fischer) and [Oscar Piloty](/source/Oscar_Piloty) in 1891.{{cite journal|first1 = Emil|last1 = Fischer|first2 = Oscar|last2 = Piloty|author-link1 = Emil Fischer|author-link2 = Oscar Piloty|journal = [Berichte der deutschen chemischen Gesellschaft](/source/Berichte_der_deutschen_chemischen_Gesellschaft)|volume = 24|issue = 2|pages = 4214–4225|year = 1891|language = de|title = Ueber eine neue Pentonsäure und die zweite inactive Trioxyglutarsäure|trans-title = About a new pentonic acid and the second inactive trioxyglutaric acid|doi = 10.1002/cber.189102402322|url = https://zenodo.org/record/1589397|access-date = 12 March 2020|archive-date = 4 June 2020|archive-url = https://web.archive.org/web/20200604184321/https://zenodo.org/record/1589397|url-status = live}} It was not until 1909 that [Phoebus Levene](/source/Phoebus_Levene) and [Walter Jacobs](/source/Walter_Abraham_Jacobs) recognised that {{nowrap | {{sm|d}}-ribose}} was a [natural product](/source/natural_product), the [enantiomer](/source/enantiomer) of Fischer and Piloty's product, and an essential component of [nucleic acid](/source/nucleic_acid)s.{{cite journal|first1 = P. A.|last1 = Levene|author-link1 = Phoebus Levene|first2 = W. A.|last2 = Jacobs|author-link2 = Walter Abraham Jacobs|journal = [Berichte der deutschen chemischen Gesellschaft](/source/Berichte_der_deutschen_chemischen_Gesellschaft)|year = 1909|volume = 42|issue = 1|pages = 1198–1203|title = Über Inosinsäure|language = de|trans-title = About inosic acid|doi = 10.1002/cber.190904201196}}{{cite journal|first1 = P. A.|last1 = Levene|author-link1 = Phoebus Levene|first2 = W. A.|last2 = Jacobs|author-link2 = Walter Abraham Jacobs|year = 1909|journal = [Berichte der deutschen chemischen Gesellschaft](/source/Berichte_der_deutschen_chemischen_Gesellschaft)|volume = 42|issue = 3|pages = 3247–3251|title = Über die Pentose in den Nucleinsäuren|trans-title = About the pentose in the nucleic acids|language = de|doi = 10.1002/cber.19090420351}}{{cite book|title = Advances in Carbohydrate Chemistry|editor1-first = Claude S.|editor1-last = Hudson|editor1-link = Claude Hudson|editor2-first = Sidney M.|editor2-last = Cantor|chapter = The Chemistry of Ribose|chapter-url = https://books.google.com/books?id=W_sk8M7jtNsC&pg=PA135|last1 = Jeanloz|first1 = Roger W.|author-link1 = Roger W. Jeanloz|last2 = Fletcher|first2 = Hewitt G.|volume = 6|pages = 135–174|publisher = [Academic Press](/source/Academic_Press)|year = 1951|isbn = 9780080562650|doi = 10.1016/S0096-5332(08)60066-1|pmid = 14894350|access-date = 15 December 2019|archive-date = 26 October 2023|archive-url = https://web.archive.org/web/20231026175827/https://books.google.com/books?id=W_sk8M7jtNsC&pg=PA135#v=onepage&q&f=false|url-status = live}} Fischer chose the name "ribose" as it is a partial rearrangement of the name of another sugar, [arabinose](/source/arabinose), of which ribose is an [epimer](/source/epimer) at the 2' carbon; both names also relate to [gum arabic](/source/gum_arabic), from which arabinose was first isolated and from which they prepared {{nowrap | {{sm|l}}-ribose}}.{{cite journal|last = Nechamkin|first = Howard|year = 1958|title = Some interesting etymological derivations of chemical terminology|url = https://archive.org/details/sim_science-education_1958-12_42_5/page/462|journal = [Science Education](/source/Science_Education_(journal))|volume = 42|issue = 5|pages = 463–474|doi = 10.1002/sce.3730420523|bibcode = 1958SciEd..42..463N}} {{multiple image|perrow = 4|total_width = 500 | align = center | direction = horizontal | image1 = Beta-D-Ribofuranose.svg | caption1 = {{nowrap | β-{{sm|d}}-ribofuranose}} | image3 = D-рибоза.png | caption3 = {{nowrap | {{sm|d}}-ribose}} | image4 = L-рибоза.png | caption4 = {{nowrap | {{sm|l}}-ribose}} | image2 = Alpha-D-Ribopyranose.svg | caption2 = {{nowrap | α-{{sm|d}}-ribopyranose}} | footer = Left: [Haworth projection](/source/Haworth_projection)s of one of each of the furanose and pyranose forms of {{nowrap | {{sm|d}}-ribose}}
Right: [Fischer projection](/source/Fischer_projection) of the [open chain](/source/open_chain) forms of {{nowrap | {{sm|d}}- and {{sm|l}}- ribose}} }} Like most sugars, ribose exists as a mixture of [cyclic forms](/source/cyclic_compound) in [equilibrium](/source/chemical_equilibrium) with its linear form, and these readily interconvert especially in [aqueous solution](/source/aqueous_solution). The name "ribose" is used in biochemistry and biology to refer to all of these forms, though more specific names for each are used when required. In its linear form, ribose can be recognised as the [pentose](/source/pentose) sugar with all of its [hydroxyl](/source/hydroxyl) [functional group](/source/functional_group)s on the same side in its [Fischer projection](/source/Fischer_projection). {{nowrap | {{sm|d}}-Ribose}} has these hydroxyl groups on the right hand side and is associated with the [systematic name](/source/IUPAC_nomenclature_of_organic_chemistry) (2''R'',3''R'',4''R'')-2,3,4,5-tetrahydroxypentanal,{{cite journal|volume = 34|issue = 4|date = July–August 2012|title = Non-IUPAC Nomenclature Systems|first = Jeffery|last = Leigh|journal = [Chemistry International](/source/Chemistry_International)|url = http://publications.iupac.org/ci/2012/3404/nn.html|access-date = 15 December 2019|publisher = [International Union of Pure and Applied Chemistry](/source/International_Union_of_Pure_and_Applied_Chemistry)|archive-date = 5 December 2019|archive-url = https://web.archive.org/web/20191205030458/http://publications.iupac.org/ci/2012/3404/nn.html|url-status = live}} whilst {{nowrap | {{sm|l}}-ribose}} has its hydroxyl groups appear on the left hand side in a Fischer projection. Cyclisation of ribose occurs via [hemiacetal](/source/hemiacetal) formation due to attack on the [aldehyde](/source/aldehyde) by the C4' hydroxyl group to produce a [furanose](/source/furanose) form or by the C5' hydroxyl group to produce a [pyranose](/source/pyranose) form. In each case, there are two possible geometric outcomes, named as α- and β- and known as [anomer](/source/anomer)s, depending on the [stereochemistry](/source/stereochemistry) at the hemiacetal carbon atom (the "anomeric carbon"). At room temperature, about 76% of {{nowrap | {{sm|d}}-ribose}} is present in pyranose forms{{cite book|chapter-url = https://books.google.com/books?id=RrKgfuRwsqsC&pg=PA227|chapter = Oxygen as a Nucleophile: Hemicetals, Hemiketals, Acetals and Ketals|pages = 224–234|title = Essentials of Organic Chemistry: For Students of Pharmacy, Medicinal Chemistry and Biological Chemistry|first = Paul M.|last = Dewick|publisher = [John Wiley & Sons](/source/John_Wiley_%26_Sons)|year = 2013|isbn = 9781118681961|access-date = 15 December 2019|archive-date = 26 October 2023|archive-url = https://web.archive.org/web/20231026175827/https://books.google.com/books?id=RrKgfuRwsqsC&pg=PA227#v=onepage&q&f=false|url-status = live}}{{rp|228}} (α:β = 1:2) and 24% in the furanose forms{{rp|228}} (α:β = 1:3), with only about 0.1% of the linear form present.{{cite journal|title = Microbial Synthesis of ᴅ-Ribose: Metabolic Deregulation and Fermentation Process|first1 = P.|last1 = de Wulf|first2 = E. J.|last2 = Vandamme|journal = [Advances in Applied Microbiology](/source/Advances_in_Applied_Microbiology)|year = 1997|volume = 44|pages = 167–214|doi = 10.1016/S0065-2164(08)70462-3|isbn = 9780120026449}} The [ribonucleoside](/source/ribonucleoside)s [adenosine](/source/adenosine), [cytidine](/source/cytidine), [guanosine](/source/guanosine), and [uridine](/source/uridine) are all [derivative](/source/derivative_(chemistry))s of β-{{sm|d}}-ribofuranose. [Metabolically important](/source/Metabolism) species that include [phosphorylated](/source/phosphorylated) ribose include [ADP](/source/adenosine_diphosphate), [ATP](/source/adenosine_triphosphate), [coenzyme A](/source/coenzyme_A),{{rp|228–229}} and [NADH](/source/Nicotinamide_adenine_dinucleotide). [cAMP](/source/Cyclic_adenosine_monophosphate) and [cGMP](/source/Cyclic_guanosine_monophosphate) serve as secondary messengers in some signaling pathways and are also ribose derivatives. The ribose [moiety](/source/moiety_(chemistry)) appears in some pharmaceutical agents, including the antibiotics [neomycin](/source/neomycin) and [paromomycin](/source/paromomycin).{{cite book|chapter = Aldopentoses—The Sugars of Nucleic Acids|chapter-url = https://books.google.com/books?id=58yxDwAAQBAJ&pg=PT63|title = Chemistry of Biomolecules|edition = 2nd|first = S. P.|last = Bhutani|publisher = [CRC Press](/source/CRC_Press)|year = 2019|isbn = 9781000650907|pages = 63–65|access-date = 15 December 2019|archive-date = 26 October 2023|archive-url = https://web.archive.org/web/20231026175826/https://books.google.com/books?id=58yxDwAAQBAJ&pg=PT63#v=onepage&q&f=false|url-status = live}} == Synthesis and sources == Ribose as its 5-phosphate ester is typically produced from glucose by the [pentose phosphate pathway](/source/pentose_phosphate_pathway). In at least some archaea, alternative pathways have been identified.{{cite journal |doi=10.1128/jb.179.19.6010-6013.1997|title=Ribose biosynthesis and evidence for an alternative first step in the common aromatic amino acid pathway in Methanococcus maripaludis|year=1997|last1=Tumbula|first1=D. L.|last2=Teng|first2=Q.|last3=Bartlett|first3=M. G.|last4=Whitman|first4=W. B.|journal=Journal of Bacteriology|volume=179|issue=19|pages=6010–6013|pmid=9324245|pmc=179501}} Ribose can be synthesized chemically, but commercial production relies on fermentation of glucose. Using genetically modified strains of ''[B. subtilis](/source/B._subtilis)'', 90 g/liter of ribose can be produced from 200 g of glucose. The conversion entails the intermediacy of gluconate and ribulose.{{cite journal |doi=10.1007/s002530051029|title=Production of d -ribose by fermentation|year=1997|last1=Wulf|first1=P. De|last2=Vandamme|first2=E. J.|journal=Applied Microbiology and Biotechnology|volume=48|issue=2|pages=141–148|pmid=9299771|s2cid=34340369|hdl=11572/262019|hdl-access=free}} Ribose has been detected in [meteorite](/source/meteorite)s.{{cite news |last1=Steigerwald |first1=Bill |last2=Jones |first2=Nancy |last3=Furukawa |first3=Yoshihiro |title=First Detection of Sugars in Meteorites Gives Clues to Origin of Life |url=https://www.nasa.gov/press-release/goddard/2019/sugars-in-meteorites |date=18 November 2019 |work=[NASA](/source/NASA) |access-date=18 November 2019 |archive-date=15 January 2021 |archive-url=https://web.archive.org/web/20210115022856/https://www.nasa.gov/press-release/goddard/2019/sugars-in-meteorites/ |url-status=live }}{{cite journal|last1 = Furukawa|first1 = Yoshihiro|first2 = Yoshito|last2 = Chikaraishi|first3 = Naohiko|last3 = Ohkouchi|first4 = Nanako O.|last4 = Ogawa|first5 = Daniel P.|last5 = Glavin|first6 = Jason P.|last6 = Dworkin|first7 = Chiaki|last7 = Abe|first8 = Tomoki|last8 = Nakamura|volume = 116|issue = 49|title = Extraterrestrial ribose and other sugars in primitive meteorites|year = 2019|journal = [Proceedings of the National Academy of Sciences of the United States of America](/source/Proceedings_of_the_National_Academy_of_Sciences_of_the_United_States_of_America)|pages = 24440–24445|doi = 10.1073/pnas.1907169116|pmid = 31740594|pmc = 6900709|bibcode = 2019PNAS..11624440F|doi-access = free}} == Structure == Ribose is an [aldopentose](/source/aldopentose) (a monosaccharide containing five [carbon](/source/carbon) atoms that, in its [open chain](/source/open_chain) form, has an [aldehyde](/source/aldehyde) [functional group](/source/functional_group) at one end). In the conventional numbering scheme for monosaccharides, the carbon atoms are numbered from C1' (in the aldehyde group) to C5'. The [deoxyribose](/source/deoxyribose) derivative found in DNA differs from ribose by having a [hydrogen](/source/hydrogen) atom in place of the [hydroxyl](/source/hydroxyl) group at C2'. This hydroxyl group performs a function in [RNA splicing](/source/RNA_splicing). The "{{sm|d}}-" in the name {{sm|d}}-ribose refers to the [stereochemistry](/source/stereochemistry) of the [chiral](/source/Chirality_(chemistry)) carbon atom farthest away from the aldehyde group (C4'). In {{sm|d}}-ribose, as in all {{sm|d}}-sugars, this carbon atom has the same configuration as in [{{sm|d}}-glyceraldehyde](/source/D-glyceraldehyde). File:Alpha-D-Ribopyranose numbered.png|α-{{sm|d}}-Ribopyranose File:Beta-D-Ribopyranose numbered.png|β-{{sm|d}}-Ribopyranose File:Alpha-D-Ribofuranose numbered.png|α-{{sm|d}}-Ribofuranose File:Beta-D-Ribofuranose Numbered.png|β-{{sm|d}}-Ribofuranose Relative abundance of forms of ribose in solution: β-{{sm|d}}-ribopyranose (59%), α-{{sm|d}}-ribopyranose (20%), β-{{sm|d}}-ribofuranose (13%), α-{{sm|d}}-ribofuranose (7%) and open chain (0.1%).{{cite journal|last1=Drew|first1=Kenneth N.|last2=Zajicek|first2=Jaroslav|last3=Bondo|first3=Gail|last4=Bose|first4=Bidisha|last5=Serianni|first5=Anthony S.|date=February 1998|title=13C-labeled aldopentoses: detection and quantitation of cyclic and acyclic forms by heteronuclear 1D and 2D NMR spectroscopy|journal=Carbohydrate Research|volume=307|issue=3–4|pages=199–209|doi=10.1016/S0008-6215(98)00040-8|doi-access=free}} For ribose residues in [nucleoside](/source/nucleoside)s and [nucleotide](/source/nucleotide), the torsion angles for the rotation encompassing the bonds influence the configuration of the respective nucleoside and nucleotide. The [secondary structure](/source/secondary_structure) of a nucleic acid is determined by the rotation of its 7 [torsion angle](/source/torsion_angle)s.{{Cite book|title=Nucleic Acids: Structures, Properties, and Functions|url=https://archive.org/details/nucleicacidsstru00bloo_123|url-access=limited|last1=Bloomfield|first1=Victor|last2=Crothers|first2=Donald|last3=Tinoco|first3=Ignacio|publisher=University Science Books|year=2000|pages=[https://archive.org/details/nucleicacidsstru00bloo_123/page/n28 19]–25|isbn=9780935702491}} Having a large amount of torsion angles allows for greater flexibility. In closed ring riboses, the observed flexibility mentioned above is not observed because the ring cycle imposes a limit on the number of torsion angles possible in the structure. Conformers of closed form riboses differ in regards to how the lone [oxygen](/source/oxygen) in the molecule is positioned respective to the [nitrogenous base](/source/nitrogenous_base) (also known as a [nucleobase](/source/nucleobase) or just a base) attached to the ribose. If a carbon is facing towards the base, then the ribose is labeled as endo. If a carbon is facing away from the base, then the ribose is labeled as exo. If there is an oxygen molecule attached to the 2' carbon of a closed cycle ribose, then the exo confirmation is more stable because it decreases the interactions of the oxygen with the base. The difference itself is quite small, but when looking at an entire chain of RNA the slight difference amounts to a sizable impact. File:2' endo.jpg|2' endo File:2' endo 3' exo.jpg|2' endo 3' exo File:3' endo 2' exo.jpg|3' endo 2' exo File:3' endo.jpg|3' endo A ribose molecule is typically represented as a planar molecule on paper. Despite this, it is typically non-planar in nature. Even between hydrogen atoms, the many constituents on a ribose molecule cause [steric hindrance](/source/steric_hindrance) and strain between them. To relieve this crowding and [ring strain](/source/ring_strain), the ring puckers, i.e. becomes non-planar.{{Cite book|title=Biochemistry|url=https://archive.org/details/biochemistrythed00voet|url-access=limited|last1=Voet|first1=Donald|last2=Voet|first2=Judith|publisher=John Wiley & Sons, Inc|year=2011|isbn=978-0470570951|pages=[https://archive.org/details/biochemistrythed00voet/page/n1181 1152], 1153}} This puckering is achieved by displacing an atom from the plane, relieving the strain and yielding a more stable conformation. Puckering, otherwise known as the sugar ring conformation (specifically ribose sugar), can be described by the amplitude of pucker as well as the [pseudorotation](/source/pseudorotation) angle. The pseudo-rotation angle can be described as either "north (N)" or "south (S)" range. While both ranges are found in double helices, the north range is commonly associated with RNA and the [A form of DNA](/source/A-DNA). In contrast, the south range is associated with [B form DNA](/source/B_form_DNA). [Z-DNA](/source/Z-DNA) contains sugars in both the north and south ranges.{{Cite journal|last1=Foloppe|first1=Nicolas|last2=MacKerell|first2=Alexander D.|date=August 1998|title=Conformational Properties of the Deoxyribose and Ribose Moieties of Nucleic Acids: A Quantum Mechanical Study|journal=The Journal of Physical Chemistry B|volume=102|issue=34|pages=6669–6678|doi=10.1021/jp9818683|bibcode=1998JPCB..102.6669F |issn=1520-6106}} When only a single atom is displaced, it is referred to as an "envelope" pucker. When two atoms are displaced, it is referred to as a "twist" pucker, in reference to the zigzag orientation.{{Cite web|url=http://fbio.uh.cu/sites/genmol/adic/na_arch.htm|title=Nucleic acid architecture|website=fbio.uh.cu|access-date=2019-10-08|archive-date=17 May 2018|archive-url=https://web.archive.org/web/20180517212501/http://fbio.uh.cu/sites/genmol/adic/na_arch.htm|url-status=dead}} In an "endo" pucker, the major displacement of atoms is on the β-face, the same side as the C4'-C5' bond and the base. In an "exo" pucker, the major displacement of atoms is on the α-face, on the opposite side of the ring. The major forms of ribose are the 3'-endo pucker (commonly adopted by RNA and A-form DNA) and 2'-endo pucker (commonly adopted by B-form DNA).{{cite book|last=Neidle|first=Stephen|chapter=The Building-Blocks of DNA and RNA|year=2008|doi=10.1016/B978-012369507-9.50003-0|title=Principles of Nucleic Acid Structure|url=https://archive.org/details/principlesnuclei00neid_308|url-access=limited|pages=[https://archive.org/details/principlesnuclei00neid_308/page/n32 20]–37|editor-last=Neidle|editor-first=Stephen|publisher=[Academic Press](/source/Academic_Press)|isbn=9780123695079}} These ring puckers are developed from changes in ring torsion angles; there are infinite combinations of angles so therefore, there is an infinite number of transposable pucker conformations, each separated by disparate activation energies. == Functions == ATP is derived from ribose; it contains one ribose, three [phosphate](/source/phosphate) groups, and an [adenine](/source/adenine) base. ATP is created during [cellular respiration](/source/cellular_respiration) from [adenosine diphosphate](/source/adenosine_diphosphate) (ATP with one less phosphate group). === Signaling pathways === Ribose is a building block in secondary signaling molecules such as [cyclic adenosine monophosphate](/source/cyclic_adenosine_monophosphate) (cAMP) which is derived from ATP. One specific case in which cAMP is used is in [cAMP-dependent signaling pathways](/source/CAMP-dependent_pathway). In cAMP signaling pathways, either a stimulative or inhibitory hormone receptor is activated by a [signal molecule](/source/signal_molecule). These receptors are linked to a stimulative or inhibitory regulative [G-protein](/source/G_protein-coupled_receptor). When a stimulative G-protein is activated, [adenylyl cyclase](/source/adenylyl_cyclase) [catalyzes](/source/Catalysis) ATP into cAMP by using Mg2+ or Mn2+. cAMP, a secondary messenger, then goes on to activate [protein kinase A](/source/protein_kinase_A), which is an [enzyme](/source/enzyme) that regulates cell [metabolism](/source/metabolism). Protein kinase A regulates metabolic enzymes by [phosphorylation](/source/phosphorylation) which causes a change in the cell depending on the original signal molecule. The opposite occurs when an inhibitory G-protein is activated; the G-protein inhibits adenylyl cyclase and ATP is not converted to cAMP. thumb|class=skin-invert-image|The difference between ribose and deoxyribose is the presence of a 2'OH |alt=|213x213px === Metabolism === Ribose is referred to as the "molecular currency" because of its involvement in intracellular energy transfers.{{citation needed|date=November 2019}} For example, [nicotinamide adenine dinucleotide](/source/nicotinamide_adenine_dinucleotide) (NAD), [flavin adenine dinucleotide](/source/flavin_adenine_dinucleotide) (FAD), and [nicotinamide adenine dinucleotide phosphate](/source/nicotinamide_adenine_dinucleotide_phosphate) (NADP) all contain the {{sm|d}}-ribofuranose [moiety](/source/moiety_(chemistry)). They can each be [derived from](/source/derivative_(chemistry)) {{sm|d}}-ribose after it is converted to [{{sm|d}}-ribose 5-phosphate](/source/ribose_5-phosphate) by the enzyme [ribokinase](/source/ribokinase).{{cite journal|last1 = Bork|first1 = Peer|author-link1 = Peer Bork|last2 = Sander|first2 = Chris|author-link2 = Chris Sander (scientist)|last3 = Valencia|first3 = Alfonso|author-link3 = Alfonso Valencia|title = Convergent evolution of similar enzymatic function on different protein folds: The hexokinase, ribokinase, and galactokinase families of sugar kinases|journal = [Protein Science](/source/Protein_Science)|volume = 2|issue = 1|pages = 31–40|year = 1993|pmid = 8382990|pmc = 2142297|doi = 10.1002/pro.5560020104|doi-access = free}}{{cite journal|last1 = Park|first1 = Jae|last2 = Gupta|first2 = Radhey S.|title = Adenosine kinase and ribokinase – the RK family of proteins|journal = [Cellular and Molecular Life Sciences](/source/Cellular_and_Molecular_Life_Sciences)|volume = 65|issue = 18|pages = 2875–2896|year = 2008|pmid = 18560757|doi = 10.1007/s00018-008-8123-1|s2cid = 11439854|pmc = 11131688}} NAD, FAD, and NADP act as electron acceptors in biochemical [redox](/source/redox) reactions in major metabolic pathways including [glycolysis](/source/glycolysis), the [citric acid cycle](/source/citric_acid_cycle), [fermentation](/source/fermentation), and the [electron transport chain](/source/electron_transport_chain). thumb|class=skin-invert-image|698x698px|The pentose phosphate pathway begins with {{sm|d}}-glucose and includes {{sm|d}}-ribose 5-phosphate as an intermediate. === Nucleotide biosynthesis=== Nucleotides are synthesized through salvage or [de novo synthesis](/source/de_novo_synthesis).{{cite book|last = Puigserver|first = Pere|chapter = Signaling Transduction and Metabolomics|year = 2018|doi = 10.1016/B978-0-323-35762-3.00007-X|title = Hematology|edition = 7th|pages = 68–78|editor1-last = Hoffman|editor1-first = Ronald|publisher = Elsevier|isbn = 9780323357623|editor2-last = Benz|editor2-first = Edward J.|editor3-last = Silberstein|editor3-first = Leslie E.|editor4-last = Heslop|editor4-first = Helen E.}} [Nucleotide salvage](/source/Nucleotide_salvage) uses pieces of previously made nucleotides and re-synthesizes them for future use. In de novo, amino acids, carbon dioxide, folate derivatives, and [phosphoribosyl pyrophosphate](/source/phosphoribosyl_pyrophosphate) (PRPP) are used to synthesize nucleotides. Both de novo and salvage require PRPP which is synthesized from ATP and ribose 5-phosphate by an enzyme called [PRPP synthetase](/source/PRPP_synthetase). == Modifications == === Modifications in nature === [Ribokinase](/source/Ribokinase) catalyzes the conversion of {{sm|d}}-ribose to [{{sm|d}}-ribose 5-phosphate](/source/Ribose_5-phosphate). Once converted, {{sm|d}}-ribose-5-phosphate is available for the manufacturing of the [amino acids](/source/amino_acids) [tryptophan](/source/tryptophan) and [histidine](/source/histidine), or for use in the [pentose phosphate pathway](/source/pentose_phosphate_pathway). The absorption of {{sm|d}}-ribose is 88–100% in the small intestines (up to 200 mg/kg·h).{{cite web|url=http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/dri_0226.shtml|title=Herbal Remedies, Supplements A-Z Index| website= PDRHealth.com| publisher= PDR, LLC |archive-url=https://web.archive.org/web/20081011083414/http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/dri_0226.shtml|archive-date=11 October 2008}} One important modification occurs at the C2' position of the ribose molecule. By adding an [O-alkyl](/source/Alkyl) group, the nuclear resistance of the RNA is increased because of additional stabilizing forces. These forces are stabilizing because of the increase of [intramolecular hydrogen bonding](/source/Hydrogen_bonding) and an increase in the [glycosidic bond](/source/glycosidic_bond) stability.{{cite conference|last1 = Hamlow|first1 = Lucas|last2 = He|first2 = Chenchen|last3 = Fan|first3 = Lin|last4 = Wu|first4 = Ranran|last5 = Yang|first5 = Bo|last6 = Rodgers|first6 = M. T.| last7 = Berden|first7 = Giel|last8 = Oomens|first8 = J.|conference = 70th International Symposium on Molecular Spectroscopy|date = June 2015|location = [University of Illinois Urbana-Champaign](/source/University_of_Illinois_Urbana-Champaign) |doi = 10.15278/isms.2015.MI13|bibcode = 2015isms.confEMI13H|title = Structual [sic] Effects of Cytidine 2'-Ribose Modifications as Determined by Irmpd Action Spectroscopy|doi-access = free}} The resulting increase of resistance leads to increases in the [half-life](/source/half-life) of [siRNA](/source/Small_interfering_RNA) and the potential therapeutic potential in cells and animals. The [methylation](/source/methylation) of ribose at particular sites is correlated with a decrease in immune stimulation.{{Cite journal|title = Nucleobase and Ribose Modifications Control Immunostimulation by a MicroRNA-122-mimetic RNA|journal=[Journal of the American Chemical Society](/source/Journal_of_the_American_Chemical_Society)|year = 2011|volume = 133|issue = 24|pages = 9200–9203|doi = 10.1021/ja202492e|pmid = 21612237|pmc = 3116021|first1 = Hayden|last1 = Peacock|first2 = Raymond V.|last2 = Fucini| first3 = Prasanna|last3 = Jayalath|first4 = José M.|last4 = Ibarra-Soza|first5 = Henry J.|last5 = Haringsma|first6 = W. Michael|last6 = Flanagan|first7 = Aarron|last7 = Willingham|first8 = Peter A.|last8 = Beal|bibcode=2011JAChS.133.9200P }} === Synthetic modifications === Along with phosphorylation, ribofuranose molecules can exchange their oxygen with [selenium](/source/selenium) and [sulfur](/source/sulfur) to produce similar sugars that only vary at the 4' position. These derivatives are more [lipophilic](/source/Lipophilicity) than the original molecule. Increased lipophilicity makes these species more suitable for use in techniques such as [PCR](/source/Polymerase_chain_reaction), [RNA aptamer](/source/Aptamer) post-modification, [antisense technology](/source/Antisense_RNA), and for phasing [X-ray crystallographic](/source/X-ray_crystallography) data.{{Cite journal| last1=Evich|first1=Marina|last2=Spring-Connell|first2=Alexander M.|last3=Germann|first3=Markus W.|date=2017-01-27|title=Impact of modified ribose sugars on nucleic acid conformation and function| journal= Heterocyclic Communications|volume=23|issue=3|pages=155–165|doi=10.1515/hc-2017-0056|s2cid=91052034|issn=2191-0197|doi-access=free}} Similar to the 2' modifications in nature, a synthetic modification of ribose includes the addition of [fluorine](/source/fluorine) at the 2' position. This [fluorinated](/source/fluorinated) ribose acts similar to the methylated ribose because it is capable of suppressing immune stimulation depending on the location of the ribose in the DNA strand. The big difference between methylation and fluorination, is the latter only occurs through synthetic modifications. The addition of fluorine leads to an increase in the stabilization of the glycosidic bond and an increase of intramolecular hydrogen bonds. == Medical uses == {{sm|d}}-ribose has been suggested for use in management of [congestive heart failure](/source/congestive_heart_failure){{cite journal|last1=Omran|first1=Heyder|last2=McCarter|first2=Dean|last3=St Cyr|first3=John|last4=Lüderitz|first4=Berndt|date=2004|title=ᴅ-Ribose aids congestive heart failure patients|journal=[Experimental & Clinical Cardiology](/source/Experimental_%26_Clinical_Cardiology)|volume=Summer|issue=9(2)|pages=117–118|pmc=2716264|pmid=19641697}} (as well as other forms of heart disease) and for [chronic fatigue syndrome](/source/chronic_fatigue_syndrome) (CFS), also called myalgic encephalomyelitis (ME) in an open-label non-blinded, non-randomized, and non-crossover subjective study.{{cite journal|last1=Teitelbaum|first1=Jacob E.|last2=Johnson|first2=Clarence|last3=St Cyr|first3=John|date=2006-11-26|title=The use of ᴅ-ribose in chronic fatigue syndrome and fibromyalgia: a pilot study.|journal=The Journal of Alternative and Complementary Medicine|volume=12|issue=9|pages=857–862|citeseerx=10.1.1.582.4800|doi=10.1089/acm.2006.12.857|pmid=17109576}} Supplemental {{sm|d}}-ribose can bypass part of the [pentose phosphate pathway](/source/pentose_phosphate_pathway), an energy-producing pathway, to produce {{sm|d}}-ribose-5-phosphate. The enzyme [glucose-6-phosphate-dehydrogenase](/source/Glucose-6-phosphate_dehydrogenase) (G-6-PDH) is often in short supply in cells, but more so in diseased tissue, such as in [myocardial](/source/Cardiac_muscle) cells in patients with cardiac disease. The supply of {{sm|d}}-ribose in the [mitochondria](/source/Mitochondrion) is directly correlated with ATP production; decreased {{sm|d}}-ribose supply reduces the amount of ATP being produced. Studies suggest that supplementing {{sm|d}}-ribose following tissue ischemia (e.g. myocardial ischemia) increases myocardial ATP production, and therefore mitochondrial function. Essentially, administering supplemental {{sm|d}}-ribose bypasses an enzymatic step in the pentose phosphate pathway by providing an alternate source of 5-phospho-{{sm|d}}-ribose 1-[pyrophosphate](/source/pyrophosphate) for ATP production. Supplemental {{sm|d}}-ribose enhances recovery of ATP levels while also reducing cellular injury in humans and other animals. One study suggested that the use of supplemental {{sm|d}}-ribose reduces the instance of [angina](/source/angina) in men with diagnosed [coronary artery disease](/source/coronary_artery_disease).{{Cite web|url=https://wa.kaiserpermanente.org/kbase/topic.jhtml?docId=hn-3949001|title=Ribose|website=wa.kaiserpermanente.org|access-date=2019-10-07|archive-date=3 March 2021|archive-url=https://web.archive.org/web/20210303060923/https://wa.kaiserpermanente.org/kbase/topic.jhtml?docId=hn-3949001|url-status=live}} {{sm|d}}-Ribose has been used to treat many [pathological](/source/pathological) conditions, such as chronic fatigue syndrome, [fibromyalgia](/source/fibromyalgia), and myocardial dysfunction. It is also used to reduce symptoms of cramping, pain, stiffness, etc. after exercise and to improve athletic performance{{Citation needed|date=December 2019}}. == References == {{Reflist}} {{Carbohydrates}}{{Purinergics}} {{Authority control}} Category:Ribose --- Adapted from the Wikipedia article [Ribose](https://en.wikipedia.org/wiki/Ribose) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Ribose?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.