Polysaccharides: Difference between revisions
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The objective of this article is to illustrate and visualize the structures and concepts of common polysaccharides<ref>[http://en.wikipedia.org/wiki/Polysaccharide Polysaccharides]</ref> that are difficult to visualize and illustrate by viewing two dimensional structures in textbooks. Structures with a 3D perspective are used to illustrate features of a molecule which can not be easily visualized using 2D structures. | The objective of this article is to illustrate and visualize the structures and concepts of common polysaccharides<ref>[http://en.wikipedia.org/wiki/Polysaccharide Polysaccharides]</ref> that are difficult to visualize and illustrate by viewing two dimensional structures in textbooks. Structures with a 3D perspective are used to illustrate features of a molecule which can not be easily visualized using 2D structures. | ||
<StructureSection load='Amylose.pdb' size='500' side='right' caption='' scene='Polysaccharides/Amylose1/ | <StructureSection load='Amylose.pdb' size='500' side='right' caption='' scene='Polysaccharides/Amylose1/7'> | ||
=== Amylose === | === Amylose === | ||
Amylose is a | Amylose is an example of a polysccharide which contains thousands of glucoses connected by α(1→4) glycosidic bonds. The initial view (<scene name='Polysaccharides/Amylose1/7'>Reset initial scene</scene>) shows yellow halos marking some of the oxygens which are involved in the 1→4 glycosidic bonds. Rotate <scene name='Polysaccharides/Amylose2/4'>amylose</scene> to view the glucopyranosyl units on edge to see that the bonds are α linkages. (Remember: With C-6 of glucose projecting to the back of the screen both bonds of the oxygen of the α linkage project down.) From this perspective you are looking down the axis of a helix that is formed as a result of the angle that is form between the glucopyranosyl residues when they are connected by the α(1→4) bonds. This characteristic of the α(1→4) bond was seen when studying [[Disaccharides|maltose]]. <scene name='Polysaccharides/Amylose3/2'>Color</scene> ends of the polymer yellow and green. <scene name='Polysaccharides/Amylose_20/1'>Amylose</scene> with 20 glucose units; <scene name='Polysaccharides/Amylose_20_2/1'>Spacefill display</scene> | ||
=== Amylopectin === | === Amylopectin === | ||