Biological macromolecules cellulose

Polymeric carbohydrates are usually encountered as distributions, so high resolution is rarely important. Of all biological macromolecules, carbohydrates are particularly amenable to analysis by GPC because hydrophobic interactions are typically weak. A section below is devoted to the analyses of carboxymethylcellulose and xanthan. Other examples of polysaccharides of interest are hyaluronic acid,62 polymers of (l-glucose,121125 heparin,126127 cellulose and chitin,128 and Mucorales extracellular polysaccharides.129... 

Girallt R, Rihouey BF, Jauneau A, Norvan C and Jarvis M (1997) Galactans and cellulose in flax fibres putative contrihutions to the tensile strength. International Journal of Biological Macromolecules, 21 179-88... 

Edible films and coatings are thin materials made from biological macromolecules (biopolymers).1 The main biopolymers used in preparing biofilms are polysaccharides2 and proteins.3,4 Among the most studied polysaccharides are pectin, cellulose and derivatives, alginates, carrageenan, chitosan and starch.1 5... 

The trans-cyclic rings of such polysaccharide derivatives are of interest in that they are very susceptible to nucleophiles, "" and sulfhydryl groups may react similarly to amino groups at near-neutral pH. "" In the case of the water-insoluble cellulose trflns-2,3-carbonate, the reaction has been applied to the insolubilization of biological macromolecules. 

Macromolecules High-molecular-weight organic molecules. Cellulose, lignin, and proteins are biological macromolecules. Humic substances are geological macromolecules. 

Geyer, U., Heinze, T., Stein, A., Klemm, D., Marsch, S., Schumann, D., Schmauder, H., 1994b. Formation, derivatization and applications of bacterial cellulose. International Journal of Biological Macromolecules 16, 343—347. 

Astley, M., Chanliaud, E., Donald, A., Gidley, M.J., 2003. Tensile deformation of bacterial cellulose composites. International Journal of Biological Macromolecules 32, 28—35. 

Woodings, C.R., 1995. The development of advanced cellulosic fibres. International Journal of Biological Macromolecules 17 (6), 305—309. 

Lima, 1. S., Lazarin, A. M., and Airoldi, C. (2005). Favorable chitosan/cellulose film combinations for copper removal from aqueous solutions. International Journal of Biological Macromolecules 36, 79-83. 

Thakur, V. K., Thakur, M. K., and Gupta, R K. [2013a]. Development of functionalized cellulosic hiopotymers by graft copolymerization. International Journal of Biological Macromolecules, 62, 44-51. doi 10.1016/j.ijbiomac.2013.08.026. 

Albertsson (Paiiition of Cell Paiiicle.s and Macromolecules, 3d ed., Wiley, New York, 1986) has extensively used particle distribution to fractionate mixtures of biological products. In order to demonstrate the versatility of particle distribution, he has cited the example shown in Table 22-14. The feed mixture consisted of polystyrene particles, red blood cells, starch, and cellulose. Liquid-liquid particle distribution has also been studied by using mineral-matter particles (average diameter = 5.5 Im) extracted from a coal liquid as the solid in a xylene-water system [Prudich and Heniy, Am. Inst. Chem. Eng. J., 24(5), 788 (1978)]. By using surface-active agents in order to enhance the water wettability of the solid particles, recoveries of better than 95 percent of the particles to the water phase were obsei ved. All particles remained in the xylene when no surfactant was added. 

There are a number of naturally occurring polymers which find technical application, including cellulose and its derivatives, starch, and rubber. In addition, a number of important biological materials, most notably the proteins, are made up of macromolecules. These will be considered briefly in the sections which follow. 

Synthetic examples include the poly(meth)acrylates used as flocculating agents for water purification. Biological examples are the proteins, nucleic acids, and pectins. Chemically modified biopolymers of this class are carboxymethyl cellulose and the lignin sulfonates. Polyelectrolytes with cationic and anionic substituents in the same macromolecule are called polyampholytes. 

Cellulose, modified by the introduction of ionic groups, is available in paper form or as a powder for use in TLC and is particularly useful for the separation of macromolecules and biological materials. Cation exchangers are produced by introducing acidic groups, e g. —0CH2S03H (sulphomethyl,... 

This subject has been of continuing interest for several reasons. First, the present concepts of the chemical constitution of such important biopolymers as cellulose, amylose, and chitin can be confirmed by their adequate chemical synthesis. Second, synthetic polysaccharides of defined structure can be used to study the action pattern of enzymes, the induction and reaction of antibodies, and the effect of structure on biological activity in the interaction of proteins, nucleic acids, and lipides with polyhydroxylic macromolecules. Third, it is anticipated that synthetic polysaccharides of known structure and molecular size will provide ideal systems for the correlation of chemical and physical properties with chemical constitution and macromolecular conformation. Finally, synthetic polysaccharides and their derivatives should furnish a large variety of potentially useful materials whose properties can be widely varied these substances may find new applications in biology, medicine, and industry. 

Cellulose, an important constituent of wood, has long chains of glucose molecules linked by glycoside bonds. These chains are cross-linked by hydrogen bonds. Many biological polymers have unusual mechanical properties, not at present matched by the properties of artificial macromolecules. For instance, arteries are... 

There have been a lot of quarrels in the early years of the twentieth century about the reality of what now are called polymers. It is the great merit of Staudinger (1920) to have proposed, contrary to the prevailing ideas, that rubber and other biological substances, such as starch, cellulose and proteins, are long chains of short repeating units linked by covalent bonds. He also coins the name "macromolecule". Since then it became clear that polymer molecules are "normal" molecules and that only their chainlike nature is "different" and imposes restrictions, but also provides new properties. 

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