Plant cellulose

The first successhil attempt to make textile fibers from plant cellulose can be traced to George Audemars (1). In 1855 he dissolved the nitrated form of cellulose in ether and alcohol and discovered that fibers were formed as the dope was drawn into the air. These soft strong nitrocellulose fibers could be woven into fabrics but had a serious drawback they were explosive, nitrated cellulose being the basis of gun-cotton (see Cellulose esters, inorganic esters). 

Most carbohydrates exist in the form of polysaccharides. Polysaccharides give stmcture to the cell walls of land plants (cellulose), seaweeds, and some microorganisms and store energy (starch in plants and glycogen in animals). They are important in the human diet and in many commercial apphcations. 

Cellulosic They are tough, transparent, hard or flexible natural polymers made from plant cellulose feedstock. With exposure to light, heat, weather and aging, they tend to dry out, deform, embrittle and lose gloss. Molding applications include tool handles, control knobs, eyeglass frames. Extrusion uses include blister packaging, toys, holiday decorations, etc. Cellulosic types, each with their specialty properties, include cellulose acetates (CAs), cellulose acetate butyrates (CABs), cellulose nitrates (CNs), cellulose propionate (CAPs), and ethyl celluloses (EC). 

Marino, B.D. and DeNiro, M.J. 1987 Isotopic analysis of archaeobotanicals to reconstruct past climates Effects of activities associated with food preparation on carbon, hydrogen and oxygen isotope ratios of plant cellulose. Journal of Archaeological Science 14 537-548. 

Marino, B.D. and McElroy, M.B. 1991 Isotopic composition of atmospheric COj inferred from carbon in C, plant cellulose. Nature 349 127-131. 

Epstein, S., Thompson, P. and Yapp, C. J. 1977 Oxygen and hydrogen isotopic ratios in plant cellulose. Science 198 1209-1215. 

The whole of a multi-cellular organism is contained by outer cell layers, which are described in biology texts, and maintained by connective tissue. Connective tissue is a novel, external biopolymer structure of multi-cellular organisms found within their new extracellular, circulating fluid compartments (see Section 8.9). As mentioned there, the main connective tissues, covalently cross-linked structures, are (1) those of plants, celluloses (polysaccharides), often cross-linked by lignin (2) those of lower animals and insects, mixed cross-linked polysaccharides and... 

Further confirmation of the identity of bacterial and plant celluloses has been obtained by x-ray studies. From dried membranes prepared by the action of A. xylinum on sucrose, Eggert and Luft18 obtained x-ray diagrams similar to those of cotton cellulose. Hibbert and Barsha16 showed that a chloroform solution of the triacetate of cellulose... 

BURTON, R.A., GIBEAUT, D.M., BACIC, A., FINDLAY, K., ROBERTS, K., HAMILTON, A., BAULCOMBE, D.C., FINCHER, G.B., Virus-induced silencing of a plant cellulose synthase gene, Plant Cell., 2000,12,691-705. 

Biologically, carbohydrates are most important as energy sources. This is especially true for monosaccharides, disaccharides, and starches. Starches also function as energy storage molecules in plants. Cellulose is an essential component of plant cell walls. 

Nonwoven materials such as cellulosic fibers have never been successfully used in lithium batteries. This lack of interest is related to the hygroscopic nature of cellulosic papers and films, their tendency to degrade in contact with lithium metal, and their susceptibility to pinhole formation at thickness of less than 100 fjim. For future applications, such as electric vehicles and load leveling systems at electric power plants, cellulosic separators may find a place because of their stability at higher temperatures when compared to polyolefins. They may be laminated with polyolefin separators to provide high-temperature melt integrity. 

DeNiro MJ, Epstein S (1979) Relationship between the oxygen isotope ratios of terrestrial plant cellulose, carbon dioxide and water. Science 204 51-53 DeNiro MJ, Epstein S (1981) Isotopic composition of cellulose from aquatic organisms. Geochim Cosmochim Acta 45 1885-1894... 

Epstein S, Yapp CJ, Hall JH (1976) The determination of the D/H ratio of non-exchangeable hydrogen in cellulose extracted from aquatic and land plants. Earth Planet Sci Lett 30 241-251 Epstein S, Thompson P, Yapp CJ (1977) Oxygen and hydrogen isotopic ratios in plant cellulose. Science 198 1209-1215... 

Polysaccharides are composed of many monosaccharides bonded together. Common polysaccharides are cellulose, starch, and glycogen. Cellulose forms the structural material of the cell walls of plants. Cellulose is a polymer of glucose and consists of thousands of glucose molecules linked in an unbranched chain (Figure 16.6). 

Synthesis of Cell Wall Polysaccharides Plant Cellulose and Bacterial Peptidoglycan 775... 

Cornelius Steelink Perhaps plant cellulosic material, after hydrolysis, could be used by soil microorganisms to produce phenolic substances, which could then be incorporated into humic acids. I think it is significant that nonlignin-derived phenols occur in podzol humic acids. 

One is shown in Fig. 4-5B. The hydrogen bonds and van der Waals forces bind the chains into sheets which are stacked to form fibers. A typical fiber of plant cellulose has a diameter of 3.5-4 nm and contains 30-40 parallel chains, each made up of 2000-10,000 glucose units. The chain ends probably overlap to form essentially endless fibers that can extend for great distances through the cell wall. They interact with other polysaccharides as is illustrated in Fig. 4-14. A single cotton... 

The most abundant structural polysaccharide is plant cellulose, a straight-chain homopolymer of glucose with a /3(1,4) linkage (see chapter 12). Cellulose is formed by the same general mechanism as glycogen, using nucleoside diphosphate sugars. Chitin, a structural polysaccharide found in insects, is also a /3(1,4) homopolymer (fig. 16.3). The... 

Both bacterial and native plant cellulose (so called cellulose I) coexist in two crystal modifications a (triclinic) and p (monoclinic). The difference consists in the H-bonding systems and in the conformation of neighboring cellulose chains. The la/lp ratio depends on the origin of the cellulose [13]. 

Cellulose A polysaccharide found in plants, consisting of long chains of glucose molecules. It maintains the structure of the cell walls and protects and strengthens the plant. Cellulose is the most abundant compound on earth made by living organisms. 

In the past few years, some impressive observations have been made by microscopists studying cells actively engaged in cellulose synthesis. It is now generally accepted by most workers that, in the bacterium A. xylinum, in most algae, and in all of the higher plants, cellulose is synthesized at the cell surface by an enzyme system localized in the plasma membrane. The notable exception to this conclusion concerns those algae which synthesize a cell wall composed of cellulosic scales such scales are synthesized intracellularly by way of the Golgi apparatus (see Ref. 57 and references cited therein). 

So what effect do these differences in stereochemistry and extent of branching have on the uses of these polysaccharides Because of the extended nature of its chains, cellulose is the most common structural component of plants. Cellulose makes up the main component of the cell wall of plants. Wood is approximately 50% cellulose, while fiber-producing plants such as flax, jute, and hemp are 65% to 80%. The seed hairs of cotton are virtually pure cellulose. The long fibers from cottonseed (up to 5 cm long and 9 to 25 jxm in diameter [Franz 1986)) are spun into thread that is then woven into fabric for clothing. Short fibers, called linters, are used as the raw materials for chemical derivatives such as cellulose acetate (see Chapter 4). 

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