bonded oxygen.
In organic chemistry, a ketose is a monosaccharide containing one ketone (>C=O) group per molecule.[1][2] The simplest ketose is dihydroxyacetone ((CH2OH)2C=O), which has only three carbon atoms. It is the only ketose with no optical activity. All monosaccharide ketoses are reducing sugars, because they can tautomerize into aldoses via an enediol intermediate, and the resulting aldehyde group can be oxidised, for example in the Tollens' test or Benedict's test.[3] Ketoses that are bound into glycosides, for example in the case of the fructose moiety of sucrose, are nonreducing sugars.[3]
Chemistry
[edit]Ketoses and aldoses can be chemically differentiated through Seliwanoff's test, where the sample is heated with acid and resorcinol.[4] The test relies on the dehydration reaction which occurs more quickly in ketoses, so that while aldoses react slowly, producing a light pink color, ketoses react more quickly and strongly to produce a dark red color. Ketoses can isomerize to aldoses through the Lobry-de Bruyn-van Ekenstein transformation.
Examples of ketoses
[edit]
All ketoses listed here are 2-ketoses, in other words, the carbonyl group is on the second carbon atom from the end:
- Trioses: dihydroxyacetone
- Tetroses: erythrulose
- Pentoses: ribulose, xylulose
- Hexoses: fructose, psicose, sorbose, tagatose
- Heptoses: sedoheptulose
- Octoses: D-manno-octulose (the basis for KDO)
- Nonoses: D-glycero-D-galacto-nonulose (the basis for neuraminic acid)
References
[edit]- ^ Lindhorst, Thisbe K. (2007). Essentials of Carbohydrate Chemistry and Biochemistry (1st ed.). Wiley-VCH. ISBN 978-3-527-31528-4.
- ^ Robyt, John F. (1997). Essentials of Carbohydrate Chemistry (1st ed.). Springer. ISBN 0-387-94951-8.
- ^ a b McMurry, John E. (2010-01-01). Organic Chemistry: With Biological Applications. Cengage Learning. p. 880. ISBN 978-0495391449.
- ^ "Seliwanoff's Test". Harper College. Archived from the original on 2017-12-16. Retrieved 2011-07-10.
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Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction