Polysaccharide branching factor

Soon after Cori and Cori showed the existence of a branching factor, Haworth, Peat, and Bourne reported the isolation from potato juice of an enzyme fraction termed Q-enzyme, which, in association with potato phosphorylase, produced a polysaccharide having the properties of amylopectin. Peat and his collaborators also presented evidence that the Q-enzyme was capable of converting linear amylose to branched amylopectin without the participation of inorganic phosphate in the reaction. They therefore concluded that the Q-enzyme is a nonphos-phorolytic enzyme. Besides being present in the potato, Q-enzyme has also been found in the wrinkled pea,the broad bean, Neisseria perfiava, and Polytomella coeca. " ... 

Molecular Structure. Most starches consist of a mixture of two polysaccharide types amylose, an essentially linear polymer, and amylopectin, a highly branched polymer. The relative amounts of these starch fractions in a particular starch are a major factor in determining the properties of that starch. 

In polysaccharides, the structural factors are even more important. A number of different saccharide units in the chain, branching of the chain, and the presence of either more-polar groups (COOH, P03H2, and S03H) or less-polar groups (OCH3... 

These molecules — proteins, polynucleotides, polysaccharides, lipids — are not necessarily any different from molecules we study in other branches of chemistry. However, there are some additional factors, arising from their biological origin, that we need to be aware of ... 

The primary structure of polysaccharides comprises a variety of factors, such as monosaccharide composition, the main chain structure, branching, and functional groups [65]. All these factors impact on bioactivities of polysaccharides. 

The viscosity of polymer dispersions depends, amongst other factors, on the structure of the macromolecules. Dispersions of soluble linear polysaccharides (such as amylose) are more viscous than dispersions of substituted polysaccharides (such as guar gum) and the less viscous dispersions are formed by branched polysaccharides (e.g. amylopectin and gum arabic). Viscosity is generally a function of radius of gyration, Radius of gyration is related to the volume... 

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