Metabolism and structure

There are two primary effects of cryosurgery direct and indirect cryodestruction. The indirect cryodestruction is the result of hypothermia and the direct cryodestruction is the result of freezing of the tissue as indicated in Table 3. Hypothermia leads to disruption of metabolism and structural integrity of the tissue. 

Plants are constantly subject to adverse environmental conditions such as drought, flooding, extreme temperatures, excessive salts, heavy metals, high-intensity irradiation and infection by pathogenic agents. Because of their immobility, plants have to make necessary metabolic and structural adjustments to cope with the stress conditions. To this end, the expression of the genetic programme in plants is altered by the stress stimuli to induce and/or suppress the production of specific proteins which are either structural proteins or enzymes for specific metabolic pathways. 

Heim, K.E. et al., Flavonoid antioxidants chemistry, metabolism and structure-activity relationships, J. Nutr. Biochem., 13, 572, 2002. 

During the last ten years, it has become apparent that calcium-dependent papain-like peptidases called calpains (EC 3.4.22.17) represent an important intracellular nonlysosomal enzyme system [35][36], These enzymes show limited proteolytic activity at neutral pH and are present in virtually every eukaryotic cell type. They have been found to function in specific proteolytic events that alter intracellular metabolism and structure, rather than in general turnover of intracellular proteins. Calpains are composed of two nonidentical subunits, each of which contains functional calcium-binding sites. Two types of calpains, i.e., /i-calpain and m-calpain (formerly calpain I and calpain II, respectively), have been identified that differ in their Ca2+ requirement for activation. The activity of calpains is regulated by intracellular Ca2+ levels. At elevated cytoplasmic calcium concentrations, the precursor procal-pain associates with the inner surface of the cell membrane. This interaction seems to trigger autoproteolysis of procalpain, and active calpain is released into the cytoplasm [37]. 

Some Differences Between the Metabolic and Structural Functions of Glutamine and Asparagine 385... 

Effects of fluorine in protein environments Metabolism and structural integrity 742... 

EFFECTS OF FLUORINE IN PROTEIN ENVIRONMENTS METABOLISM AND STRUCTURAL INTEGRITY... 

The important bacterial storage material poly-hydroxybutyric acid is related metabolically and structurally to the lipids. This highly reduced polymer is made up of D-(3-hydroxybutyric acid units in ester linkage, about 1500 residues being present per chain. The structure is that of a compact right-handed coil with a twofold screw axis and a pitch of 0.60 nm.a Within bacteria it often occurs in thin lamellae 5.0 nm thick. Since a chain of 1500 residues stretches to 440 nm, there must be 88 folds in a single chain. Present in both cytoplasmic granules and in membranes,b polyhydroxybutyrate can account for as much as 50% of the total carbon of some bacterial In E. coli and many other bacteria polyhydroxybutyrate is present in a lower molecular mass form bound to calcium polyphosphates, proteins, or other macromolecules.d e It has also been extracted from bovine serum albumin and may be ubiquitous in both eukaryotes and prokaryotes.d/e The polymer may function in formation of Ca2+ channels in membranes.b/d... 

Heim K, Tagliaferro A, Bobilya D. 2002. Flavonoid antioxidants Chemistry, metabolism and structure-activity relationships. J Nutr Biochem 13 572-584. 

Stephens, L., Hawkins, P. T., and Downes, C. P. (1989) Metabolic and structural evidence for the existence of a third species of polyphosphoinositide in cells D-phosphatidyl-myo-inositol 3-phosphate. Biochem J. 259, 267-276. 

The C4 cycle can be viewed as an ATP-dependent C02 pump that delivers C02 from the mesophyll cells to the bundle-sheath cells, thereby suppressing photorespiration (Hatch and Osmond, 1976). The development of the C4 syndrome has resulted in considerable modifications of inter- and intracellular transport processes. Perhaps the most striking development with regard to the formation of assimilates is that sucrose and starch formation are not only compartmented within cells, but in C4 plants also may be largely compartmented between mesophyll and bundle-sheath cells. This has been achieved together with a profound alteration of the Benson-Calvin cycle function, in that 3PGA reduction is shared between the bundle-sheath and mesophyll chloroplasts in all the C4 subtypes. Moreover, since C4 plants are polyphyletic in origin, several different metabolic and structural answers have arisen in response to the same problem of how to concentrate C02. C4 plants have three distinct mechanisms based on decarboxylation by NADP+-malic enzyme, by NAD+-malic enzyme, or by phosphoenolpy-ruvate (PEP) carboxykinase in the bundle-sheath (Hatch and Osmond, 1976). 

Engal, D. W., Fowler, B. A. Copper and Cadmium-Induced Changes in the Metabolism and Structure of Molluscan Gill Tissue in Marine Pollution Functional Responses (Vemberg, W. B., Calabrese, F. P., Thurberg, F. P., Vemberg, F. J., eds.), New York, Academic Press 1979... 

Lecithins are widely distributed in the membranes of cells having both metabolic and structural functions. Dipalmityl lecithin is a very effective surface active agent preventing adherence due to surface tension of the inner surfaces of the lungs. Most phospholipids have a saturated fatty acid in the Cl position but an unsaturated fatty acid in the C2 position. 

Glycoproteins constitute the most diverse of these classes of glycoconjugates. Their substructures, the glycopeptides, occur as natural and artificial degradation products of glycoproteins during metabolism and structural analysis, respectively, or they are obtained synthetically in... 

The isolation of the proteins of fish muscle is still in its beginning, but is a necessary preliminary step to gain a deeper insight into the metabolism and structure of this tissue, thus providing a basis to attack the problems of storage. For the present, our description will be limited to some pure... 

Roberts, G.C. and Hudson, A.P. 2006. Transcriptome profiling of Saccharomyces cerevisiae during a transition from fermentative to glycerol-based respiratory growth reveals extensive metabolic and structural remodeling. Mol. Gen. Genomics 276,170-186. 

Hildebrand, R.L., The Role of Phosphonates in Living Systems, CRC Press, Boca Raton, 1983. Hildebrand, R.L., Curley-Joseph, J, Lubansky, H.J., and Henderson, T.O., Biology of alkylphosphonic acids. A review of the distribution, metabolism, and structure of naturally occurring alkylphosphonic acids, in Topics in Phosphorus Chemistry, Vol. 11, John Wiley Sons, New York, 1983, pp. 297-338. Hudson, H.R., Quasi-phosphonium intermediates and compounds, in Topics in Phosphorus Chemistry, Vol. 11, John Wiley Sons, New York, 1983, pp. 339-436. 

Simple sugars may be converted to closely related chemical compounds. Several of these are important metabolic and structural components of living organisms. 

Chrostek-Maj and Czeczotko 1995a Drexler et al. 1995b). A transient decrease in blood pressure was reported in rats administered 506 mg/kg carbon disulfide once by gavage (Hoffmann and Klapperstuck 1990). ECG changes were seen at 373 and 506 mg/kg, while heart rate decreased at 632 mg/kg. The other studies on animals attest to the adverse effects of carbon disulfide on the cardiovascular system (Antov et al. 1985 Chandra et al. 1972 Wronska-Nofer et al. 1980). These effects included lipid droplet infiltration in the coronary arteries, metabolic and structural changes in the myocardium and the aorta, and myocardial lesions characterized by necrosis, interstitial edema, and cellular infiltrate. 

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