Carbohydrate biological function

Carbohydrates are the first major class of biomolecules we ll discuss. We ll see in this chapter what the structures and primary biological functions of carbohydrates are, and then in Chapter 29, we ll return to the subject to see how carbohydrates are biosynthesized and degraded in organisms. 

Blocking the anomeric reactivity allows one not only to inhibit enzymes, which interfere with biological functions, but also to mimic glycosides by stable compounds of pharmacological relevance. Hence, modifications of the anomeric centre of carbohydrates are also reviewed, as well as compounds of that type which have found application as drugs. 

The most important biological function of carbohydrates is to provide energy. Most current dietary recommendations suggest that about 55% of total caloric requirements be provided by carbohydrates. 

In both their industrial and biological functions, the 3-dimensional characteristics of carbohydrates are important. Many of these stereochemical features are described for carbohydrates in the classic text by Stoddart (2). The inqportance of stereochemistry is underscored by the unique chemical and physical properties of the individual sugars, many of which are configurational isomers. Stereochemistry also plays a role in detentlining the properties of polysaccharides. Molecular shape is as significant for the properties of an industrially modified starch as it is for the recognition of one particular blood type and the rejection of others. 

R. Schauer, Chemistry, metabolism and biological functions of sialic acids, Adv. Carbohydr. Chem. Biochem. 40 131 (1982). 

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