Sugars, Polysaccharides, and Glycoproteins

The simple sugars, or monosaccharides, are poly-hydroxyaldehydes (aldoses) or polyhydroxyketones (ketoses). All have the composition (CH20)p, hence the family name carbohydrate. A typical sugar, and the one with the widest distribution in nature, is glucose. 

D-Pructose (Fru), a ketose that is a close structural and metabolic relative of D-glucose. It occurs in honey and fruit juices in free form, in the disaccharide sucrose (table sugar) as a 5-membered furanose ring, and in other oligosaccharides and polysaccharides. 

Altrose (Alt) Allose (All) Glucose (Glc) Mannose (Man) Gulose (Gul) Idose (Ido) Galactose (Gal) Talose (Tal)  

Ring forms of sugars are also often drawn according to the Fischer convention making use of elongated bent lines to represent ordinary simple bonds  

Haworth structures are easy to draw and unambiguous in depicting configurations, but they also do not show the spatial relationships of groups attached to other rings correctly. For this reason conformational formulas of the fype described in Section 2 and shown in Fig. 4-4 are used most often in this book. 

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