Fig 

 (a) 



(b) 



(c) 



22. Parts of a molecular chain of cellulose. Hydrogen atoms are omitted. 



Diagrammatic two-dimensional representation of 4 )S-glucose residues united in 

 a chain. This represents the organization of a molecular chain as first proposed 

 by Meyer and Mark, and corresponds to fig. 21. 



Diagrammatic two-dimensional representation of 4 ^-glucose residues in a chain 

 following the suggestions of Stuart. The consecutive glucose residues lie in a 

 zigzag about the 1 :4 C — O — C link. This kind of folding allows the cellobiose 

 residues to fit into the unit cell 10-3 A. long without the strain imposed on the 

 C — O — C bond necessary in the Meyer and Mark model. 

 In figs. 22(a) and (b) the rings of glucose residues are of necessity drawn flat in 

 the plane of the page. This figure is intended to convey some idea of the spatial 

 relationships of the ring. The ring oxygen (open circle) and carbon 5 lie in the 

 front of the drawing and carbons 2 and 3 behind. Carbons 1 and 4 can be 

 regarded as lying in the plane of the page. 



