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An aldose, along with ketose, is a monosaccharide (a simple sugar) that contains only one aldehyde (−CH=O) group per molecule, whereas ketose contains a ketone group. The chemical formula takes the form C_n(H₂O)_n. The simplest possible aldose is the diose glycolaldehyde, which only contains two carbon atoms.^[1]

Because they have at least one asymmetric^[2] carbon center, aldoses with three or more carbon atoms exhibit stereoisomerism. Aldoses containing stereogenic centers can exist in either a D- form or L- form. The determination is made based on the chirality of the penultimate carbon (the second-furthest from the aldehyde), where alcohol groups on the right of the Fischer projection result in D-aldoses, and epimers with alcohols on the left result in L-aldoses. Biological systems tend to recognize D-aldoses more than L-aldoses.

Examples of aldose include glycolaldehyde, glyceraldehyde, erythrose, threose, ribose, arabinose, xylose, lyxose, allose, altrose, glucose, mannose, gulose, idose, talose, and galactose. ^[3]

An aldose differs from a ketose in that it has a carbonyl group at the end of the carbon chain instead of in the middle. This allows ketoses and aldoses to be chemically differentiated through Seliwanoff's test.^[4] An aldose may isomerize to a ketose through the Lobry-de Bruyn-van Ekenstein transformation. Aldose and ketose, although differ in structures, also perform in different roles.

List of aldoses

Diose: glycolaldehyde
Triose: glyceraldehyde
Tetroses: erythrose, threose
Pentoses: ribose, arabinose, xylose, lyxose
Hexoses: allose, altrose, glucose, mannose, gulose, idose, galactose, talose

References

^ Berg, J.M. (2006). Biochemistry (6th ed.). New York: W. H. Freeman and Company.
^ "Difference Between Aldose and Ketose". Difference Between. Retrieved 2016-03-28.
^ "Difference Between Aldose and Ketose". Difference Between. Retrieved 2016-03-28.
^ "Seliwanoff's Test". Harper College. Retrieved 2011-07-10.

This biochemistry article is a stub. You can help Wikipedia by expanding it.

[1] Berg, J.M. (2006). Biochemistry (6th ed.). New York: W. H. Freeman and Company.

[2] "Difference Between Aldose and Ketose". Difference Between. Retrieved 2016-03-28.

[3] "Difference Between Aldose and Ketose". Difference Between. Retrieved 2016-03-28.

[4] "Seliwanoff's Test". Harper College. Retrieved 2011-07-10.

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 [[File:D-Glyceraldehyde 2D Fischer.svg|thumb|140px|[[Fischer projection]] of {{smallcaps all|D}}-[[glyceraldehyde]]]]
-An '''aldose''' is a [[monosaccharide]] (a simple sugar) that contains only one [[aldehyde]] (−CH=O) group per [[molecule]]. The [[chemical formula]] takes the form C<sub>''n''</sub>(H<sub>2</sub>O)<sub>''n''</sub>. The simplest possible aldose is the [[diose]] [[glycolaldehyde]], which only contains two [[carbon]] [[atom]]s.<ref>{{cite book| last=Berg| first=J.M.| edition=6th| title=Biochemistry| year=2006| publisher=W. H. Freeman and Company| location=New York}}</ref>
+An '''aldose,''' along with ketose, is a [[monosaccharide]] (a simple sugar) that contains only one [[aldehyde]] (−CH=O) group per [[molecule]], whereas ketose contains a ketone group. The [[chemical formula]] takes the form C<sub>''n''</sub>(H<sub>2</sub>O)<sub>''n''</sub>. The simplest possible aldose is the [[diose]] [[glycolaldehyde]], which only contains two [[carbon]] [[atom]]s.<ref>{{cite book| last=Berg| first=J.M.| edition=6th| title=Biochemistry| year=2006| publisher=W. H. Freeman and Company| location=New York}}</ref>
-Because they have at least one asymmetric carbon center, aldoses with three or more carbon atoms exhibit [[stereoisomerism]]. Aldoses containing stereogenic centers can exist in either a {{smallcaps all|D}}- form or {{smallcaps all|L}}- form. The determination is made based on the chirality of the penultimate carbon (the second-furthest from the aldehyde), where alcohol groups on the right of the [[Fischer projection]] result in {{smallcaps all|D}}-aldoses, and [[epimer]]s with alcohols on the left result in {{smallcaps all|L}}-aldoses. Biological systems tend to recognize {{smallcaps all|D}}-aldoses more than {{smallcaps all|L}}-aldoses.
+Because they have at least one asymmetric<ref>{{Cite web|url=http://www.differencebetween.net/object/comparisons-of-food-items/differences-between-aldose-and-ketose/|title=Difference Between Aldose and Ketose|website=Difference Between|language=en-US|access-date=2016-03-28}}</ref> carbon center, aldoses with three or more carbon atoms exhibit [[stereoisomerism]]. Aldoses containing stereogenic centers can exist in either a {{smallcaps all|D}}- form or {{smallcaps all|L}}- form. The determination is made based on the chirality of the penultimate carbon (the second-furthest from the aldehyde), where alcohol groups on the right of the [[Fischer projection]] result in {{smallcaps all|D}}-aldoses, and [[epimer]]s with alcohols on the left result in {{smallcaps all|L}}-aldoses. Biological systems tend to recognize {{smallcaps all|D}}-aldoses more than {{smallcaps all|L}}-aldoses.
+Examples of aldose include glycolaldehyde, glyceraldehyde, erythrose, threose, ribose, arabinose, xylose, lyxose, allose, altrose, glucose, mannose, gulose, idose, talose, and galactose. <ref>{{Cite web|url=http://www.differencebetween.net/object/comparisons-of-food-items/differences-between-aldose-and-ketose/|title=Difference Between Aldose and Ketose|website=Difference Between|language=en-US|access-date=2016-03-28}}</ref>
-An aldose differs from a [[ketose]] in that it has a [[carbonyl]] group at the end of the carbon chain instead of in the middle. This allows ketoses and aldoses to be chemically differentiated through [[Seliwanoff's test]].<ref>{{cite web|title=Seliwanoff's Test| publisher=Harper College| accessdate=2011-07-10| url=http://www.harpercollege.edu/tm-ps/chm/100/dgodambe/thedisk/carbo/seli/seli.htm}}</ref> An aldose may [[isomer]]ize to a ketose through the [[Lobry-de Bruyn-van Ekenstein transformation]].
+An aldose differs from a [[ketose]] in that it has a [[carbonyl]] group at the end of the carbon chain instead of in the middle. This allows ketoses and aldoses to be chemically differentiated through [[Seliwanoff's test]].<ref>{{cite web|title=Seliwanoff's Test| publisher=Harper College| accessdate=2011-07-10| url=http://www.harpercollege.edu/tm-ps/chm/100/dgodambe/thedisk/carbo/seli/seli.htm}}</ref> An aldose may [[isomer]]ize to a ketose through the [[Lobry-de Bruyn-van Ekenstein transformation]]. Aldose and ketose, although differ in structures, also perform in different roles.
 ==List of aldoses==

Revision as of 22:25, 28 March 2016

List of aldoses

See also

References