Biological regulation

The concentrations of the principal elements in marine and freshwaters are given in Figure 11. The concentrations of biologically regulated components, ie, C, N, P, and Si, vary with depth and are markedly influenced by the growth, distribution, and decay of phytoplankton and other organisms. The concentrations of other constituents, especially the salts, ie, Cl ,, and, are remarkably constant and are different from those in fresh... 

Department of Biological Regulation, The Weizmann Institute of Science, Rehovot, Israel... 

PROTEIN PHOSPHORYLATION IS OF FUNDAMENTAL IMPORTANCE IN BIOLOGICAL REGULATION 391... 

Gandy, S. and Greengard, P. Processing of Alzheimer Ab-amloid precursor protein cell biology, regulation, and role in Alzheimer disease. Int. Rev. Neurobiol. 35 29-50, 1994. 

Tessier, A., Buffle, J. and Campbell, P. G. C. (1994). Uptake of trace metals by aquatic organisms. In Chemical and Biological Regulation of Aquatic Systems, eds. Buffle, J. and DeVitre, R. R., Lewis Publishers, Boca Raton, FL, pp. 197-230. 

Change in the fashion biologicals regulated (elimination of the Establishment and Product licenses, both replaced with a Biological License Application or BLA). 

Buffte, J. (1991), Ed., Chemical and Biological Regulation of Aquatic Processes, in press. 

Buffle J, Stumm W (1994) In Buffle J, Devitre RR (eds) Chemical and biological regulation of aquatic systems. CRC Press, Boca Raton, Florida, p 1... 

Biological Regulations and Examples of Associated Cellular Rhythms... 

Phosphorylation of serine, threonine, and tyrosine side-chain OH groups of proteins by kinases and their dephosphorylation by protein phosphatases provides an important mechanism for biological regulation. Tyrosine phosphatases are not metalloenzymes but the serine/threonine phosphatases contain a bimetallic site. 

Ciechanover, A., Orian, A., and Schwartz, A.L. (2000). Ubiquitin-mediated proteolysis Biological regulation via destruction. BioEssays 22,442-451. 

Since CoQio underlies biologic regulation and metabolism, we focused on early absorption parameters (0-4 h after ingestion). Additionally, longterm accumulation in blood and tissue was examined after consecutive dosing during 2 weeks. 

Edmond H. Fischer and Edwin G. Krebs Physiology/Medicine Reversible protein phosphorylation in biological regulation... 

Fischer and Krebs were awarded the Nobel Prize in Physiology or Medicine lor their work on biological regulation mechanisms in 1992. 

A wide variety of compounds and treatments have been reported to activate microsomal glucose-6-phosphatase phosphotransferase. These are described briefly below the possible relevance of the action of a number of these factors in the biological regulation of activities of the enzyme has been considered in Section II,C,3. 

I. REGULATION IN BIOLOGICAL SYSTEMS A. Biological Regulations Homeostatic or Epigenetic... 

When one refers to biological regulations, one usually thinks of homeostatic regulations, that is, regulations that tend to maintain the level of variables in the vicinity of a supposedly optimal value, usually well below the level that would be reached if the system operated at its maximal rate. I shall discuss these mechanisms in Section I.D. Note that this homeostatic type of regulation operates essentially like a thermostat in practice, even where the objective is constancy, the system usually oscillates around the chosen value because this regulation proceeds by alternate upward and downward corrections. 

As shown notably by the thermodynamic school of Brussels,9,10 systems maintained far from equilibrium and endowed with appropriate non-linearities and feedback interactions may display such nontrivial behaviors as sustained oscillations and multiple steady states (see papers by I. Prigogine and G. Nicolis in this volume). Even though the structures studied are much simpler than biological systems, this type of work provides a firm fundamental basis, not sufficient but absolutely necessary, for the future understanding of such processes as cell differentiation. Clearly, the sustained oscillations and multiple steady states displayed by simpler systems are related, respectively, with the two types of biological regulation described above. 

Such photorelease of various substrates is of much interest for the study of both semiochemical processes and biological regulation and communication. 

A feature of most cancer cells is that they exhibit a disturbance of the ordered structures and biological regulation observed in normal cells. Evidence is presented, based on studies of living cells and on electron microscopy, which indicates that the arrangement of molecules within the plasma membrane and of subsurface microfilaments has certain properties that are similar to those of liquid crystals. These liquid crystalline properties are disturbed in malignant cells. 

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