ribose
American Heritage Dictionary:
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ri·bose
(rī'bōs') 
n.
A pentose sugar, C5H10O5, occurring as a component of riboflavin, nucleotides, and nucleic acids.
n.
A pentose sugar, C5H10O5, occurring as a component of riboflavin, nucleotides, and nucleic acids.
[German, alteration of English arabinuse, a kind of sugar : (GUM) ARAB(IC) + -IN + -OSE2.]
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Five-carbon sugar found in RNA. (In DNA the corresponding sugar is the closely related deoxyribose.) A ribose molecule combined with adenine, guanine, cytosine, or uracil forms a nucleoside; adding a phosphate group forms a nucleotide. The ribose of one nucleotide joins with the phosphate of the next to form the RNA backbone. Ribose phosphates are components of various coenzymes and are used by microorganisms in synthesizing histidine.
For more information on ribose, visit Britannica.com.
A water-soluble pentose, also known as D-ribose (see first structural formula), which, together with 2-deoxy-D-ribose, makes up the carbohydrate constituents of nucleic acids, which are found in all living organisms.
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A pentose (five-carbon) sugar which occurs as an intermediate in the metabolism of glucose; especially important in the nucleic acids and various coenzymes: occurs widely in foods.
A five-carbon sugar readily synthesized in the body and provided in small amounts by the diet from ripe fruits and vegetables. Ribose serves as an energy substrate for the resynthesis of ATP.
Columbia Encyclopedia:
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ribose
ribose (rī'bōs), monosaccharide carbohydrate of universal distribution in living tissue, found in ribonucleic acid (RNA; see nucleic acid), free nucleotides, and various coenzymes. Its close relative, deoxyribose, is a constituent of deoxyribonucleic acid (DNA); ribose has one more oxygen atom in its molecule than deoxyribose. Some of the best procedures for the laboratory preparation of ribose involve the hydrolysis of yeast nucleic acid.
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symbol: Rib; ribo-pentose. The d enantiomer, as β-d-ribofuranose, forms the glycose moiety of all ribonucleosides, ribonucleotides, and ribonucleic acids, and of ribose phosphates, various glycosides, some coenzymes, and some forms of vitamin B12.
| riboprobe, ribophorin, ribonucleotide reductase | |
| ribose nucleic acid, ribose-5-phosphate epimerase, ribose-phosphate pyrophosphokinase |
Mosby's Dental Dictionary:
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ribose
n
A 5-carbon sugar that occurs as a component of ribonucleic acid.
Wikipedia on Answers.com:
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Ribose
| D-Ribose | |
|---|---|
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D-Ribose |
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| Identifiers | |
| CAS number | 50-69-1  |
| PubChem | 5779 |
| EC-number | 200-059-4 |
| DrugBank | DB01936 |
| ChEMBL | CHEMBL1159662  |
| Properties[1][2] | |
| Molecular formula | C5H10O5 |
| Molar mass | 150.13 g/mol |
| Appearance | white solid |
| Melting point |
95 °C, 368 K, 203 °F |
| Solubility in water | very soluble |
| Chiral rotation [α]D | −21.5° (H2O) |
| Related compounds | |
| Related aldopentoses | Arabinose Xylose Lyxose |
| Related compounds | Deoxyribose |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Ribose is an organic compound with the formula C5H10O5; specifically, a monosaccharide (simple sugar) with linear form H−(C=O)−(CHOH)4−H, which has all the hydroxyl groups on the same side in the Fischer projection.
The term may refer to either of two enantiomers: it almost always to D-ribose, which occurs widely in nature and is discussed here; or to its synthetic mirror image L-ribose, which is not found in nature and is of limited interest.
D-Ribose was first reported in 1891 by Emil Fischer. It is a C'-2 carbon epimer of the sugar D-arabinose (both isomers of which are named for their source, gum arabic) and ribose itself is named as a transposition of the name of arabinose.[3]
Ribose constitutes the backbone of RNA, a biopolymer that is the basis of genetic transcription. It is related to deoxyribose, as found in DNA. Once phosphorylated, ribose can become a subunit of ATP, NADH, and several other compounds that are critical to metabolism like the secondary messengers cAMP and cGMP.
Structure
Ribose is an aldopentose (a monosaccharide containing five carbon atoms) that, in its open chain form, has an aldehyde 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 derivative found in DNA differs from ribose by having a hydrogen atom in place of the hydroxyl group at C2'.
Like many monosaccharides, ribose occurs in water as the linear form H−(C=O)−(CHOH)4–H and either of two ring forms: ribofuranose ("C3'-endo"), with a five-membered ring, and ribopyranose ("C2'-endo"), with a six-membered ring. The ribofuranose form predominates in aqueous solution.
The "D-" in the name D-ribose refers to the stereochemistry of the chiral carbon atom farthest away from the aldehyde group (C4'). In D-ribose, as in all D-sugars, this carbon atom has the same configuration as in D-glyceraldehyde.
Phosphorylation
In biology, D-ribose must be phosphorylated by the cell before it can be used. Ribokinase catalyzes this reaction by converting D-ribose to D-ribose 5-phosphate. Once converted, D-ribose-5-phosphate is available for the manufacturing of the amino acids tryptophan and histidine, or for use in the pentose phosphate pathway. The absorption of D-ribose is 88–100% in the small intestines (up to 200 mg/kg/hr).[4]
References
- ^ The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (11th ed.), Merck, 1989, ISBN 091191028X, 8205.
- ^ Weast, Robert C., ed. (1981). CRC Handbook of Chemistry and Physics (62nd ed.). Boca Raton, FL: CRC Press. p. C-506. ISBN 0-8493-0462-8..
- ^ Nechamkin, Howard (1958). "Some interesting etymological derivations of chemical terminology". Science Education 42: 463. doi:10.1002/sce.3730420523.
- ^ [1][dead link]
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