Control of synthesis

They are very effective ways of retaining specific metal ions in a nonexchanging site. In effect, each M.porphyrin is a new element , different from the parent metal ion compare free Mg2+ with chlorophyll, and its organic part is different for each metal ion (see (5) below). Thus a metal element becomes like S or P in non-exchanging selectivity similar in a sense to that of organo-metallic chemistry (see Section 2.16). The concentrations of the complexes has then separate controls of synthesis based on novel transcription factors. 

Stehle, P, Riirst, P, Ratz, R., and Rau, H. (1988). Isotachophoresis of quaternary 4,4 -bipyridyIium salts-analytical control of synthesis and purification procedures.. Chromatogr. 449, 299—305. 

Sutherland, I. W. 1979. Microbied exopolysaccheirides Control of synthesis and acylation. In Microbial Polysaccharides and Polysaccharases. R. C. W. Berkeley, G. W. Gooday and D. C. Ellwood, (Editors). Academic Press, New York, pp. 1-34. Tacquet, A., Tison, F. and Devulder, B. 1961. Bactericidal action of yogurt on mycobacteria. Ann. Inst. Pasteur. 100, 581-587. (French)... 

Since the synthesis of both classes of these MTs has not yet been shown to be specifically regulated by one metal rather than another, any specificity of function may result from molecular recognition in the binding of ions to these polypeptides. It is clear that in M. guttatus, Cu, but not Cd, is bound to certain proteins perhaps because of the different chemical properties of the ions (although as yet transcriptional/translational control of synthesis of these proteins cannot be totally rejected). Furthermore, although both Cu and Cd form PC complexes, it is possible that PC complexes with essential metal ions could be processed differently from those with non-essential metal ions. 

COHERENT CONTROL OF SYNTHESIS AND PURIFICATION OF CHIRAL MOLECULES... 

FIG. 2. The control of synthesis of sucrose and starch in photosynthetic cells, and the role of metabolite modulation, including that by fructose 2,6-bisphosphate. 

F. Organic Chemistry in Action, 2nd ed., Elsevier Amsterdam, 1996. (c) Ho, T.-L. Polarity Control of Synthesis, Wiley New York, 1991. 

The mineralocorticoids have a main action on the distal tubules in the kidney to increase sodium absorption, with concomitant increased excretion of K and H. Aldosterone is the main endogenous mineralocorticoid. It is produced in the outermost layer of the adrenal cortex (the zona glomerulosa). An excessive secretion of mineralocorticoids (e.g. in Conn s syndrome) causes marked salt and water retention, with a resultant increase in the volume of extracellular fluid, alkalosis, hyperkalaemia and often hypertension. A decrease in secretion (e.g. Addison s disease) causes a disproportional loss of Na compared to fluid loss, so osmotic pressure of the extracellular fluid is reduced. This results in an increase in intracellular compared to extracellular fluid volume. The concomitant decrease in excretion of K results in hyperkalaemia with some decrease in bicarbonate. The control of synthesis and release of aldosterone is complex and involves both the renin-angiotensin system and the electrolyte composition of the blood. As with other... 

---