Search results
Results From The WOW.Com Content Network
Simple monosaccharides have a linear and unbranched carbon skeleton with one carbonyl (C=O) functional group, and one hydroxyl (OH) group on each of the remaining carbon atoms. Therefore, the molecular structure of a simple monosaccharide can be written as H(CHOH) n (C=O)(CHOH) m H, where n + 1 + m = x; so that its elemental formula is C x H 2x ...
The table shows all aldoses with 3 to 6 carbon atoms, and a few ketoses. For chiral molecules, only the ' D-' form (with the next-to-last hydroxyl on the right side) is shown; the corresponding forms have mirror-image structures. Some of these monosaccharides are only synthetically prepared in the laboratory and not found in nature.
Osazone formation was developed by Emil Fischer, [3] who used the reaction as a test to identify monosaccharides. The formation of a pair of hydrazone functionalities involves both oxidation and condensation reactions. [4] Since the reaction requires a free carbonyl group, only "reducing sugars" participate.
Fischer projection of D-glyceraldehyde. Like most carbohydrates, simple aldoses have the general chemical formula C n (H 2 O) n.Because formaldehyde (n=1) and glycolaldehyde (n=2) are not generally considered to be carbohydrates, [1] the simplest possible aldose is the triose glyceraldehyde, which only contains three carbon atoms.
When the carbonyl is in position 1, forming an formyl group (−CH=O), the sugar is called an aldohexose, a special case of aldose. Otherwise, if the carbonyl position is 2 or 3, the sugar is a derivative of a ketone , and is called a ketohexose , a special case of ketose ; specifically, an n -ketohexose .
Carbohydrate NMR spectroscopy is the application of nuclear magnetic resonance (NMR) spectroscopy to structural and conformational analysis of carbohydrates.This method allows the scientists to elucidate structure of monosaccharides, oligosaccharides, polysaccharides, glycoconjugates and other carbohydrate derivatives from synthetic and natural sources.
An oligosaccharide has both a reducing and a non-reducing end. The reducing end of an oligosaccharide is the monosaccharide residue with hemiacetal functionality, thereby capable of reducing the Tollens’ reagent, while the non-reducing end is the monosaccharide residue in acetal form, thus incapable of reducing the Tollens’ reagent. [2]
Deoxyribose, or more precisely 2-deoxyribose, is a monosaccharide with idealized formula H−(C=O)−(CH 2)−(CHOH) 3 −H. Its name indicates that it is a deoxy sugar, meaning that it is derived from the sugar ribose by loss of a hydroxy group. Discovered in 1929 by Phoebus Levene, [2] deoxyribose is most notable for its presence in DNA.