Sodium pump definition

This simple experiment was important in that it clearly established the key notion that cellular extrusion of sodium ions by the sodium pump was coupled to metabolism. Because in this and subsequent experiments of the same sort the electrochemical gradient for sodium was known precisely, and since the fluxes of sodium (and later potassium) both into and out of the cell could be measured independently, this study also laid the groundwork for a theoretical definition of active transport, a theory worked out independently by Ussing in the flux ratio equation for transepithelial active transport of ions (see below). 

Panderi and Parissi-Poulou developed a microbore liquid chromatographic method for the simultaneous determination of benazepril hydrochloride and hydrochlorothiazide in pharmaceutical dosage forms [30]. The use of a BDS C-18 microbore analytical column was found to result in substantial reduction in solvent consumption and in increased sensitivity. The mobile phase consisted of a mixture of 25 mM sodium dihydrogen phosphate buffer (pH 4.8) and acetonitrile (11 9 v/v), pumped at a flow rate of 0.4 mL/min. Detection was effected at 250 nm using an ultraviolet absorbance detector. The intra- and inter-day relative standard deviation values were less than 1.25% (n = 5), while the relative percentage error was less than 0.9% (n = 5). The detection limits obtained according to the IUPAC definition were 0.88 and 0.58 pg/mL for benazepril hydrochloride and hydrochlorothiazide, respectively. The method was applied to the quality control of commercial tablets and content uniformity test, and proved to be suitable for rapid and reliable analysis. 

Biological membranes show anisotropy, as their molecules are preferentially ordered in a definite direction in the plane of the membrane, and the coupling between chemical reactions (scalar) and diffusion flow (vectorial) can take place. Almost all outer and inner membranes of the cell have the ability to undergo active transport. Sodium and potassium pumps operate in almost all cells, especially nerve cells, while the active transport of calcium takes place in muscle cells. The proton pumps operate in mitochondrial membranes, chloroplasts, and the retina. 

These free electrons give sodium and the other metals their high electrical conductivity. Pump in an electron at one end of a metal wire, and another electron from an almost identical orbital pops out at the other end. The delocalized electrons of the metallic bond ensure that little energy is required for this process, making metals highly conductive and the preferred material for power lines. It also led the renowned materials scientist Sir Alan Cottrell to propose a new definition of a metal Metals, he wrote in a 1960 article, contain free electrons. ... 

Upflow saturators use a bed of undissolved sodium fluoride as a bed in which water is forced through upward. Water under pressure is distributed through a spider-type distributor head located at the bottom of the tank. This head contains hundreds of tiny slits in which water is forced under pressure through these slits and flows upward through the sodium fluoride bed at a controlled rate to ensure the desired 18,000 ppm of fluoride solution. An upflow saturator requires water pressure at a minimum of 20 psi to a maximum of 100 psi, and the flow into the saturator is regulated at 2 gpm. Because the introduction of water to the bottom of the saturator constitutes a definite cross-connection, a certified backflow preventer must be installed on the water supply line to the saturator along with anti-siphon valve on the solution feed pump (2). 

---