Biochemical fibers

Among the natural fibers are cellulose, the primary structural component of plants and bacterial cell walls animal fibers such as wool and silk and biochemical fibers. Plant fibers are composed of cellulose (see Figure 1), lignin (see Figure 2), or similar compounds animal fibers are composed of protein (see Figure 3). 

Control of relative humidity is needed to maintain the strength, pHabiUty, and moisture regain of hygroscopic materials such as textiles and paper. Humidity control may also be required in some appHcations to reduce the effect of static electricity. Temperature and/or relative humidity may also have to be controlled in order to regulate the rate of chemical or biochemical reactions, such as the drying of varnishes, the appHcation of sugar coatings, the preparation of synthetic fibers and other chemical compounds, or the fermentation of yeast. 

Biomechanical Machines. The mechanical properties of fibrous polypeptides could be put to use for the commercial production of fibers (qv) that are more elastic and resiUent than available synthetics (see Silk). The biochemical properties of proteins could also be harnessed for the conversion of mechanical energy to chemical energy (35). 

Mercerized cellulose fibers have improved luster and do not shrink further. One of the main reasons for mercerizing textiles is to improve their receptivity to dyes. This improvement may result more from the dismption of the crystalline regions rather than the partial conversion to a new crystal stmcture. A good example of the fundamental importance of the particular crystal form is the difference in rate of digestion by bacteria. Bacteria from cattle mmen rapidly digest Cellulose I but degrade Cellulose II very slowly (69). Thus aHomorphic form can be an important factor in biochemical reactions of cellulose as well as in some conventional chemical reactions. 

Girsch, S. J., and Hastings, J. W. (1978). The properties of mnemiopsin, a bioluminescent and light sensitive protein purified by hollow fiber techniques. Mol. Cell. Biochem. 19 113-124. 

Ridgway, E. B., and Ashley, C. C. (1967). Calcium transients in single muscle fibers. Biochem. Biophys. Res. Commun. 29 229-234. 

In addition to effects on biochemical reactions, the inhibitors may influence the permeability of the various cellular membranes and through physical and chemical effects may alter the structure of other subcellular structures such as proteins, nucleic acid, and spindle fibers. Unfortunately, few definite examples can be listed. The action of colchicine and podophyllin in interfering with cell division is well known. The effect of various lactones (coumarin, parasorbic acid, and protoanemonin) on mitotic activity was discussed above. Disturbances to cytoplasmic and vacuolar structure, and the morphology of mitochondria imposed by protoanemonin, were also mentioned. Interference with protein configuration and loss of biological activity was attributed to incorporation of azetidine-2-carboxylic acid into mung bean protein in place of proline. 

The smooth muscle cell does not respond in an all-or-none manner, but instead its contractile state is a variable compromise between diverse regulatory influences. While a vertebrate skeletal muscle fiber is at complete rest unless activated by a motor nerve, regulation of the contractile activity of a smooth muscle cell is more complex. First, the smooth muscle cell typically receives input from many different kinds of nerve fibers. The various cell membrane receptors in turn activate different intracellular signal-transduction pathways which may affect (a) membrane channels, and hence, electrical activity (b) calcium storage or release or (c) the proteins of the contractile machinery. While each have their own biochemically specific ways, the actual mechanisms are for the most part known only in outline. 

How do the Predicted Free Energy Changes Fit With the Revised Model Biochemical Experiments with Fibers... 

Both mechanics and biochemical studies of muscle fibers suggest there is more than one force generating state. Crossbridges are thought to attach initially as... 

The histopathological features of muscle samples from patients with myotonic dystrophy are not particularly distinctive. Early changes appear to be a selective atrophy of type 1 fibers, and hypertrophy of type 2 fibers, but the biochemical and/or physiological basis of these possibly related phenomena is not known. The incidence of degenerating fibers increases with age, although the presence of internally nucleated muscle fibers in early stages of the disease suggests that the muscle retains... 

Palytoxin (PTX) is one of the most potent marine toxins known and the lethal dose (LD q) of the toxin in mice is 0.5 Mg/kg when injected i.v. The molecular structure of the toxin has been determined fully (1,2). PTX causes contractions in smooth muscle (i) and has a positive inotropic action in cardiac muscle (4-6). PTX also induces membrane depolarization in intestinal smooth (i), skeletal (4), and heart muscles (5-7), myelinated fibers (8), spinal cord (9), and squid axons (10). PTX has been demonstrated to cause NE release from adrenergic neurons (11,12). Biochemical studies have indicated that PTX causes a release of K from erythrocytes, which is followed by hemolysis (13-15). The PTX-induced release of K from erythrocytes is depress by ouabain and that the binding of ouabain to the membrane fragments is inhibited by PTX (15). 

QURESHI A A, SAEED A s, FAROOQ A K (2002) Effects of Stabilized rice bran, its soluble and fiber fractions on blood glucose levels and serum lipid parameters in humans with diabetes mellitus Types 1 2. J Nutri Biochem, 13 175-87. 

Weber, J. (1976). Untersuchungen fiber Zellwandgehalt und -zusammensetzung der Kartoffelknollen. Biochem Physiol Pfianzen 169, 589-594. 

Trettnak W., Wolfbeis O.S., Fiber optic cholesterol biosensor with an oxygen optrode as the transducer Anal. Biochem. 1990 184 124. 

Boisde G., Harmer A., Chemical and biochemical sensing with optical fibers and waveguides, Artech House, Boston-London, 1996. 

Tempelman L.A., King K.D., Anderson G.P., Ligler F.S., Quantitating staphylococcal enterotoxin B in diverse media using a portable fiber optic biosensor, Anal. Biochem. 1996 223 50-57. 

Muhlethaler, K. Electron Micrographs of Plant Fibers. Biochem. bio-physica Acta 3, 15 (1949). 

Pasquier B, Armand M, Guillon F, Castelain C, Borel P, Barry JL, Pieroni G and Lairon D. 1996. Viscous soluble dietary fibers alter emulsification and lipolysis of triacylglycerols in duodenal medium in vitro. J Nutr Biochem 7 293—302. 

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