Editing Sucrose (section)

===Structural O-α-<small>D</small>-glucopyranosyl-(1→2)-β-<small>D</small>-fructofuranoside===
In sucrose, the [[monomer]]s glucose and fructose are linked via an ether bond between C1 on the [[glucosyl]] subunit and C2 on the [[fructosyl]] unit. The bond is called a [[glycosidic linkage]]. Glucose exists predominantly as a mixture of α and β "pyranose" [[anomer]]s, but sucrose has only the α form. Fructose exists as a mixture of five [[tautomer]]s but sucrose has only the β-<small>D</small>-fructofuranose form. Unlike most [[disaccharide]]s, the glycosidic bond in sucrose is formed between the reducing ends of both glucose and fructose, and not between the reducing end of one and the non-reducing end of the other. This linkage inhibits further bonding to other saccharide units, and prevents sucrose from spontaneously reacting with cellular and circulatory macromolecules in the manner that glucose and other reducing sugars do. Since sucrose contains no anomeric hydroxyl groups, it is classified as a non-[[reducing sugar]].

Sucrose crystallizes in the [[monoclinic]] [[space group]] P2<sub>1</sub> with room-temperature lattice parameters ''a'' = 1.08631&nbsp;nm, ''b'' = 0.87044&nbsp;nm, ''c'' = 0.77624&nbsp;nm, β = 102.938°.<ref>{{Cite journal|journal = Acta Crystallogr|year = 1952|volume = 5|pages = 689–90|doi = 10.1107/S0365110X52001908|title = The crystal structure of sucrose|author1=Beevers, C. A. |author2=McDonald, T. R. R. |author3=Robertson, J. H. |author4=Stern, F. |issue = 5| bibcode=1952AcCry...5..689B }}</ref><ref>{{cite journal|doi=10.1107/S0021889891002492|title=Sucrose, a convenient test crystal for absolute structures|year=1991|last1=Hynes|first1=R. C.|last2=Le Page|first2=Y.|journal=Journal of Applied Crystallography|volume=24|issue=4|page=352|bibcode=1991JApCr..24..352H }}</ref>

The purity of sucrose is measured by [[polarimetry]], through the rotation of [[Polarization (waves)|plane-polarized light]] by a sugar solution. The [[specific rotation]] at {{cvt|20|°C}} using yellow "sodium-D" light (589&nbsp;nm) is +66.47°. Commercial samples of sugar are assayed using this parameter. Sucrose does not deteriorate at ambient conditions.