Biochemical control

Interpretable high-resolution structural infomiation (e.g. preservation of dimensions, or correlation of the stmctiiral detail with a physiologically or biochemically controlled state) is therefore obtained exclusively from samples in which life has been stopped very quickly and with a sufficiently high time resolution for the cellular dynamics [19]. Modem concepts for specimen preparation therefore try to avoid traditional, chemical... 

Classifier systems are in some respects a scientific solution looking for a problem because they are currently the least used of the methods discussed in this book. However, their potential as a disguised expert system is substantial and they are starting to make inroads into the fields of chemical and biochemical control and analysis. 

An excess of zinc will cause problems in humans. Excessive doses can lead to biochemical control system damage, while doses slightly higher than optimal can cause disorders in iron and copper metabolism, resulting in incurable anemia, decrease in activity of zinc protein enzymes, and pancreas and kidney damage (Boularbah et ah, 1999 Seiler et ah, 1994). Increased levels of zinc have been observed in nuclei of neoplastic cells and in cases of acute dental caries, however its role in these diseases has not been explained. 

The same basic biochemical control mechanism causes contraction of the smooth muscle as well as secretion of aldosterone. The binding of angiotensin to its receptor activates a membrane phospholipase-C. It catalyses the hydrolysis of phosphoinositide phosphatidylinositol bis-phosphate to produce the two intracellular messengers, inositol trisphosphate (IP3) and diacylglycerol (DAG). 

Kohn. M.C. Melnick, R.L. (1993) Species differences in the production and clearance of 1,3-butadiene metabolites a mechanistic model indicates predominantly physiological not biochemical control. Carcinogenesis, 14, 619-628... 

Phase transition in gels in response to biochemical reactions [27,28]. Polymer gels were synthesized in which an enzyme (urease) or a biologically active protein (lectin) was immobilized. The volume phase transitions were observed in such gels when biochemical reactions took place. Such mechano-biochemical gels will be used in devices such as, sensors, selective absorbers, and biochemically controlled drug release. 

This section summarizes recent data obtained from biophysical techniques on the nature of the metal ion, catalytic, and modifier sites of E. coli glutamine synthetase. Distance relationships between these sites are given in Fig. 27. This enzyme has many diverse modes of biochemical control. Recent data presented in this review demonstrate that progress is being made toward understanding the structural basis for the control of enzymic catalysis. When x-ray data become available 127), the amino acid groups at the catalytic site will be known and will provide further details concerning the mechanism of the enzymic reaction. 

Hundreds of biochemical reactions take place even in the cells of relatively simple microorganisms. Living systems have evolved a sophisticated hierarchy of controls that permits them to maintain a stable intracellular environment. These controls ensure that substances required for maintenance and growth are produced in amounts that are adequate without being excessive. Biochemical controls have developed in such a way that the cell can make adjustments in response to a changing external environment. Adjustments are needed because the temperature, ionic strength, acid concentration, and concentration of nutrients present in the... 

Redeker KR, Manley SL, Walser M, Cicerone RJ (2004) Physiological and Biochemical Controls over Methyl Halide Emissions from Rice Plants. Global Biogeochem Cycles 18 GB1007... 

Kaczmarek L, Levitan I (1987) Neuromodulation the biochemical control of neuronal excitability. Oxford University Press, New York... 

When translated into dollar values, the losses amount to more than 20 billion each year. Proper understanding of allelopathic processes, particularly for plant growth, could lead to several beneficial effects (for example, biochemically control of weeds) on agricultural production. 

Transcription is the synthesis of RNA from a DNA template. The primary transcript may then be modified or processed to the final product. Eventually, the RNA product is degraded to nucleotides. While all of these reactions are potential sites for control of gene expression, most control of gene expression is transcriptional. This is an example of a general principle of biochemical control Pathways are controlled at the first committed step, and RNA synthesis is the first committed step of gene expression. 

Savageau, M.A. The behaviour of intact biochemical control systems. In Current Topics in Cellular Regulation. Vol. 6. B.L. Horecker and E.R. Stadtman (eds.). pp. 63-130. Academic Press, New York 1972. 

Based on current knowledge, it seems likely that whatever form the final hypothesis may take, it will center around what happens when the formation of ATP or NADPH, or both, is inhibited after interference with the photochemical reactions of the chloroplasts. Hopefully, the postulates will serve as models that can be subjected to rigorous and sophisticated experimentation, and will be modified as our knowledge of biochemical control systems in higher plants increases. 

Biochemical control systems (i.e., zymogens, activators, etc.). It is in this area that large advances should be forthcoming in the next decade or so. The sophisticated selective breakdowns of proteins to form functional products are among the most important biochemical control reactions found in tissues. 

The major caseins exist in milk as highly structured, spherical aggregates, consisting of 450 to 10,000 subunits (3), commonly referred to as micelles. The important physico-chemical properties of the micelles are summarized in Table 3. Casein micelles are synthesized in vivo by biochemically controlled processes., which have not been totally characterized (5). Even... 

Lewis, N.G. and Davin, L.B. (1998) The biochemical control of monolignol coupling and structure during lignan and lignin biosynthesis. ACS Symp. Sen, 697, 334—61. 

Because the RPP cycle is an exporter of fixed carbon, regulation of the cycle at several points may be insufficient to prevent the intermediates from being consumed by other metabolic processes. In addition to the biochemical controls discussed above there is also compartmentation. 

Howarth, R. W., Marino, R., and Cole, J. J. (1988b). Nitrogen fixation in freshwater, estuarine, and marine ecosystems. 2. Biochemical controls. Limnol. Oceanogr. 33, 688—701. 

Twort, C.H.C. (1994). The intracellular calcium store in airway smooth muscle. In Airways Smooth Muscle Biochemical Control of Contraction and Relaxation (eds D. Raeburn and M.A. Giembycz), pp. 97-115. Virkhauser Verlag, Basel. 

Glass L. and Kauffman S. A. (1973). The logical analysis of continuous, nonlinear biochemical control networks. Journal of Theoretical Biology. 39, pp 103-129. 

Savageau, M. A. (1972). The behavior of intact biochemical control systems. Curr. Top. Cell. Reg. 6, 63-130. 

After we had achieved a stable reversal of disease in these patients, the dose of enzyme was empirically reduced by 50% every 9 months in order to determine the minimum amount required for biochemical control of the illness [29]. All patients remained clinically and biochemically stable for 9 months at an enzyme dose of 30 U/kg every 2 weeks. However, 9 months after the dose was reduced to... 

Kokufuta E, Tanaka T. Biochemically controlled thermal phase transition of gels. Macromolecules 1991 24 1605-1607. 

Conclusion Towards an Overarching Framework for Biochemical Controls... 

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