Pentose


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pentose

[′pen‚tōs]
(biochemistry)
Any one of a class of carbohydrates containing five atoms of carbon.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Pentose

 

a monosaccharide that contains five carbon atoms per molecule. In nature, pentoses do not occur in the free state but are present in various glycosides and polysaccharides that are commonly found in plants; these include arabinose and xylose. The pentoses ribose and 2-deoxyribose are constituents of nucleic acids. Nucleoside-diphosphate sugars participate in the insertion of arabinose and xylose into complex carbohydrates. Ribose in the form of ribose-5-phosphate, which takes part in the biosynthesis of nucleotides, is formed as an intermediate product in photosynthesis and in the pentose-phosphate cycle. Pentoses are converted by mineral acids into furfurol, a valuable raw material in the chemical industry.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Martin Williams, Vice President of Business Development, Sales and Marketing at Pentose told MLO "Inactine has killed every virus we've tried."
However, there are a limited number of studies on the expression of pentose phosphate pathway-related proteins in breast cancer.
Phosphogluconate dehydrogenase (Pgd) is an enzyme that converts 6-phosphogluconate to ribulose 5phosphate in the oxidative branch of the pentose phosphate pathway, which produces NADPH as well as purine nucleotides [28].
Pocsi, "Co-ordination of the nitrate and nitrite assimilation, the glutathione and free radical metabolisms, and the pentose phosphate pathway in Penicillium chrysogenum," Journal of Basic Microbiology, vol.
Yellow color marked pathway is the pentose phosphate pathway; the number in parenthesis is the gene copy found in the genome; GalK: galactokinase (EC 2.71.6); GalE: UDP-glucose 4-epimerase (EC 5.1.3.2); GalT: UDP-glucose-hexose-1-phosphate uridylyltransferase (EC 2.7.7.12); GalU: UTP-glucose-1- phosphate uridylyltransferase (EC 2.7.79); PGM: phosphoglucomutase (EC 5.4.2.2); XI: xylose isomerase (EC 5.3.1.5); XK: xylulokinase (EC 2.71.17); AI: arabinose isomerase (EC 5.3.1.4); RK: ribulokinase (EC 2.71.16); RI: ribose 5-phosphate isomerase (EC 5.3.1.6); RPE: ribulose-phosphate 3-epimerase (EC 5.1.3.1); TKL: transketolase (EC 2.2.1.1); TAL: transaldolase (EC 2.2.1.2).
However, the main disadvantage of this organism is lacking of mechanisms to take up pentose sugars as substrate.
The pathway can be considered in two phases: the irreversible oxidative phase comprising the reactions catalyzed by glucose 6-phosphate dehydrogenase, lactonase and 6-phosphogluconate dehydrogenase; and the reversible, non-oxidative phase involving the rest of the pathway, then: Regulation of the pentose phosphate pathway: The flow of metabolites through the pathway is regulated at the glucose 6-phosphate dehydrogenase reaction and the 6-phosphogluconate dehydrogenase by the availability of NADP +.
The increase in glycolysis activates the enzyme fructose 1, 6 diphosphatase which activates the pentose phosphate pathway liberating NADPH.
Metabolic network of Corynebacterium glutamicum consists of the EMP pathway, TCA cycle, Pentose phosphate pathway and gluconeogenesis to represent the central metabolism (Fig.
But the pentose in the nucleotide might take part in the pentose phosphate pathway to produce NADPH which could attenuate the damage by free radicals.
Substances stimulating glucose catabolism by the oxidative reactions of the pentose phosphate pathway in human erythrocytes.
Evidence that the pentose sugar ribose stimulates ATP synthesis and improves cardiac function led us to test the possibility that ribose increases tolerance to myocardial ischaemia in patients with coronary artery disease (CAD).