Salts, translocation

Salts are readily absorbed by the roots while esters are readily absorbed by foliage. Translocation occurs, with accumulation principally at the meristematic regions of shoots and roots. Acts as a growth inhibitor... 

As a class of tissue, epithelia demarcate body entry points, predisposing a general barrier function with respect to solute entry and translocation. The intestine is lined with enterocytes, which are polarized cells with their apical membrane facing the intestinal lumen that is separated by tight junctions from the basolateral membrane that faces the subepithelial tissues. In addition to their barrier function, the epithelia that line the GI tract serve specialized functions that promote efficient nutrient digestion and absorption and support other organs of the body in water, electrolyte, and bile salt homeostasis. The homeostatic demand on GI tissue that results from this dual function may pose special transport consideration compared with solute translocation across biologically inert barriers. 

The pore formation mechanism presented in Fig. 7 (45) is appealing for many reasons. It illustrates the significance of thermal fluctuations, because the pore is indeed induced by fluctuations in spontaneous salt ion concentrations in the vicinity of the membrane. Furthermore, the pore mediated ion leakage mechanism is very rapid, and it occurs in a collective manner through redistribution and diffusion of lipids around the pore. Also, recent data indicate that the pores also mediate flip-flop events across a membrane (46), which provides one plausible mechanism for lipid translocation, which in turn is of central importance in processes such as programmed cell death. Other dynamic processes in lipid systems are expected to be equally complex, which highlights the importance to understand the interplay between thermal fluctuations, physiologic conditions, and collective phenomena. 

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