Monosaccharides Other Than Glucose

D-Mannose and D-galactose are readily translated into six-membered Haworth structures. The a anomers only are shown. 

Both of these are epimers of glucose that is, neglecting the anomeric carbon, they differ from glucose in the configuration at just one carbon atom-—mannose at C-2, galactose at C-4. 

The most common aldopentose is D-ribose, the sugar present in RNA. 

Question Translate D-ribose into five- and six-membered Haworth structures. Give the ft anomers only. 

The only known crystalline form of D-ribose is /3-D-ribopyranose, but in solution the a and /3 anomers of both pyranose and furanose forms occur. 

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In this article, the authors have endeavored to summarize the methods of synthesis and the proofs of constitution of all the known methyl ethers of D-glucopyranose and D-glucofuranose. Acyclic glucose ethers are not considered in this review. Later articles will deal with monosaccharides other than glucose. It has not been possible to discuss in full all the reactions involved, but to offset this disadvantage the bibliography has been made as complete as possible and tables have been compiled of the physical properties of the methyl-D-glucoses and of their more important derivatives. 

The two major monosaccharides, other than glucose, that enter the bloodstream from the diet are fructose from sucrose and galactose from lactose. In both cases these hexoses are metabolically transformed and enter the early stages of the glycolytic pathway. 

The ability of the enzyme to combine a-n-glucose-l-phosphate with a number of monosaccharides other than D-fructose shows that the enzyme is far less specific with regard to substituents for the second half of the sucrose molecule, n-fructose. 

From these experiments we conclude that for pure and highly crystalline celluloses, a fast decomposition to glucose with minimum by-products is possible. Carbohydrates, containing other sugar units than glucose, are hydrolyzed accompanied by destruction of monosaccharides. The conditions for complete breakdown of cellulose are too severe for other polysaccharides. The problem of achieving optimum hydrolysis conditions is, of course, not a new one and must be solved for each polysaccharide or polysaccharide-containing material. The problem was not pursued further. 

Monosaccharides may possess functionalities other than hydroxyls. Amino sugars are aldoses or ketoses which have a hydroxyl group replaced by an amino functionality. 2-Amino-2-deoxy-glucose is one of the most abundant amino sugars it is a constituent of the polysaccharide chitin. It also appears in mammalian glycoproteins, linking the sugar chain to the protein. Monosaccharides may also be substituted with sulfates and phosphates. Furthermore, deoxy functions can often be present, and important examples of this class of monosaccharides are L-fucose and L-rhamnose. 

Glucose is an aldohexose, where aldo- indicates that it is an aldehyde, -hex- designates the number of carbons, and -ose is the suffix used for carbohydrates. Some other common monosaccharides are fructose, a 2-ketohexose that is isomeric with glucose, and ribose, an aldopentose that contains one fewer carbons than glucose. 

During diarrhea, the small intestine retains its ability to actively transport monosaccharides such as glucose. Glucose actively carries sodium with water and other electrolytes. Because the WHO-ORS has a high sodium concentration, U.S. physicians have been reluctant to use it in well-nourished children. Yet controlled comparative studies describe more favorable results with the WHO-ORS than with parenteral fluids. Amino acids promote sodium transport and act as... 

Sugars are structurally the simplest carbohydrates. They are the structural unit which makes up the other types of carbohydrates. Monosaccharides are single (mono=one) sugars. Important monosaccharides include ribose (C5H10O5), glucose (C6H12O6), and fructose (same formula but different structure than glucose). 

Monosaccharide units can be linked together by condensation (a reaction that joins together two molecules with the elimination of a simple molecule, water in this instance). The resulting linkage is called the gly-cosidic bond, and condensation usually involves the OH group on C-1 of one unit and an OH group on a C atom other than C-1 (often C-4) in the second unit. Condensation of two monosaccharides yields a disaccharide, such as sucrose, which contains a glucose and... 

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