Gradient, chemical

Major differences are the following (1) Facihtated diffusion can operate bidirectionally, whereas active transport is usually unidirectional. (2) Active transport always occurs against an electrical or chemical gradient, and so it requires energy. 

For the same quantity of electricity, twice as many water molecules are electrolyzed at the cathode than at the anode, producing a chemical gradient of molecular water. As a consequence of the reactions, two supplemental ionic species, H+ and OH (in addition to the migration of existing anions and cations in the pore fluid under the electrical field), are generated, and can have a significant influence on local conductance. 

Chemical gradients Across Earth s layers of core solids Sea depth Atmosphere height Concentrations in liquids behind barriers... 

The whole body movement of bacterial cells uses flagella motors which drive a peculiar motion of runs and rotations. In this fumbling manner they follow vaguely external gradients of attractants such as sources of food, light or magnetic fields, and they move in the opposite sense in a repellent chemical gradient by chemotaxis. 

Multi-cellular organisms Plants and animals As above Chemical hormones in vesicle stores As above Extra cytoplasmic organic chemical gradients (internal vesicle stores) Sound and light external... 

Planetary nebulae (PNe) offer the opportunities 1) to study stellar nucleosynthesis in the advanced phases of stellar evolution of stars in the wide mass range - -O. S to Mq and 2) to probe radial and as well horizontal/vertical chemical gradients in spiral galaxies by the time of formation of their progenitors. 

This requires the participation of a protein transporter. Molecules move spontaneously toward lower concentration (chemical gradient) and opposite charge (electrical gradient). Moving in the opposite direction requires the input of energy. 

Let us initially look at a semiconducting binary oxide Ai gO in a chemical gradient an oxygen potential gradient. Reduction takes place on the low oxygen... 

Wilkinson, P. C. (1990). How do leukocytes perceive chemical gradients FEMS Microbiol. Immunol. 64, 303-12. 

There are two major ways in which liposomes have been radiolabeled by stably trapping the radionuclide in the liposome interior (i) use of second molecule encapsulated in liposome and (ii) chemical gradient with pH or ammonium sulfate. In the first method, a radionuclide is incubated with a lipophilic chelator and then mixed with an aliquot of liposomes encapsulating a second molecule. Once the lipophilic chelator carries the radionuclide across the lipid bilayer, the second molecule interacts with the radionuclide-chelator causing the radionuclide to become trapped within the interior of the liposome. This interaction may be due to the second molecule having a higher affinity for the radionuclide than the original lipophilic chelator. An... 

They serve as both separator and electrolyte. These are generally inorganic materials that are impervious barriers to gases and liquids. They allow one or more kinds of ions to migrate through their lattice when a potential gradient or a chemical gradient is present. These types of separators are beyond the scope of this article. 

Keywords mineral systems, mantle fluids, chemical gradients... 

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