Constructed from glucose residues

Figure 2. Two maltotetraose models constructed from residues of glucose having different D. They have identical linkage bond and torsion angles.

Mention has already been made of two polymers that can be obtained naturally from living animals silk (from the silkworm) and wool (from sheep). They are proteins made of various amino acids both are used in textiles. Other biologically derived polymers are also familiar such as wood, starch, and some sugars. We will not cover these in detail here. However, certain cellulosics we will discuss briefly since they are compared to synthetic fibers later. Cellulose is the primary substance of which the walls of vegetable cells are constructed and is largely composed of glucose residues. It may be obtained from wood or derived in very high purity from cotton fibers, which are about 92% pure cellulose. 

From these results, algal xylan appears to be analogous to lichenin, which is constructed of 1 —> 3 and 1 —> 4 linkages between D-glucose residues, and is thus different from the known xylans185 of land plants. 

Cellulose is the primary substance of which the walls of vegetable cells are constructed and is largely composed of glucose residues. It may be obtained from wood or derived in very high purity from cotton fibers, which are about 92% pure cellulose. 

Fig. 4.3 A hypothetical model for the location of five lysyl residues around the substrates bound to potato tuber UDP-glucose pyrophosphorylase, constructed based on the results of the comparative affinity labeling.541 (Reproduced with permission from J. Biochem., 110, 713 (1991)).

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