Magnesium ions sodium pump

Life evolved in seawater. Therefore a consideration of the relative compositions of seawater and extracellular and intracellular fluids is relevant to an analysis of metal ion utilization. Seawater contains a high concentration of sodium ions, and, in lesser amounts, potassium, calcium, and magnesium ions. These cations are also found in living cells in varying amounts. It is necessary, however, for the cell to maintain pumps to keep the individual concentration of these ions within it to appropriate limits. For example, sodium ions are found in high concentrations in seawater and in extracellular fluids, but potassium ions are concentrated within living cells. Sodium ions must be pumped out of the cells, and systems are available to do this. Pumps are also available to control the intracellular concentrations of other cations. The transition metal ions, such as zinc, are also found in seawater, but in much, much lower concentrations, and they are, as described above, equally rare within cells. 

The most fundamental bioelectric processes of life occur at ihe level of membranes. In living things, there are many processes that create segregation of charge and so produce electric fields within cells and tissues. Bioelectric events start when cells expend metabolic energy to actively transport sodium outside the cell and potassium inside the cell. The movement of sodium, potassium, chloride, and, to a lesser extent, calcium and magnesium ions occurs through the functionality of molecular pumps and selective channels within the cell membrane. 

The purified commercial di-n-butyl d-tartrate, m.p. 22°, may be used. It may be prepared by using the procedure described under i o-propyl lactate (Section 111,102). Place a mixture of 75 g. of d-tartaric acid, 10 g. of Zeo-Karb 225/H, 110 g. (136 ml.) of redistilled n-butyl alcohol and 150 ml. of sodium-dried benzene in a 1-litre three-necked flask equipped with a mercury-sealed stirrer, a double surface condenser and an automatic water separator (see Fig. Ill, 126,1). Reflux the mixture with stirring for 10 hours about 21 ml. of water collect in the water separator. FUter off the ion-exchange resin at the pump and wash it with two 30-40 ml. portions of hot benzene. Wash the combined filtrate and washings with two 75 ml. portions of saturated sodium bicarbonate solution, followed by lOu ml. of water, and dry over anhydrous magnesium sulphate. Remove the benzene by distillation under reduced pressure (water pump) and finally distil the residue. Collect the di-n-butyl d-tartrate at 150°/1 5 mm. The yield is 90 g. 

The question for the nutritionist and clinician is Which Mg-dependent function is most sensitive to depletion of the body s magnesium and to hypomagnesemia The answer is probably ion transport systems, such as the calcium pump and Np,K-ATPase. The impaired activity of these ion pumps is likely to be responsible for the neuromuscular problems that present with an Mg deficiency. The defects would involve a difficulty in maintaining the normal movements of calcium, sodium, and potassium ions required for nerve conduction and muscle contraction,... 

The refinery clarification equipment has the capability of adding any of the chemicals mentioned above. However, lime clarification was chosen as the method to be used. The combined secondary effluent and the plant return streams (5.64 MGD) are pumped from the surge ponds to the rapid mix basin in the clarifier. The rapid mix basin has two compartments in series and each compartment has a high speed mixer. Lime and sodium hydroxide are added to the first compartment and these are vigorously mixed with the secondary effluent in both compartments. As a result, the pH of the effluent from the rapid mix basin is raised to between 10.8 to 11.0. At this pH, much of the bicarbonate in the water reacts with the lime and forms an insoluble calcium carbonate and the magnesium in the water reacts with hydroxyl ions to form insoluble magnesium hydroxide. 

For the separation and quantification of the cations and anions, a Metrohm AG ion chromatograph (1C), was utilized. The ions analyzed were lithium (Li", sodium (Na" ), ammonium (NILj ), calcium (Ca " ), magnesium (Mg " ), potassium (K ), fluoride (F ), chloride (Cl ), nitrite (N02 ), nitrate (3 ), phosphate (P04 ) and sulphate (S04 ). The instmment was equipped with a 733 IC analytical separation systems, a 732 IC detector, 709 IC pump, 753 Suppressor module and a 750 Auto sampler. A Metrosep Anion Dual 2 column is used for anion detection with the suppressor module at a flow rate of 0.8 ml min while Metrosep C2-100 is used for the cation detection without the suppressor unit at a flow rate of 1.0 ml min Before doing the ion analysis, the IC was calibrated using a series of standard solutions of different concentrations containing the same ion. 

Two of the important proteins involved in the transport of ions across the gUls are the sodium-potassium transporter and the magnesium-calcium transporter. Called pumps, these transporters consume cellular energy and require an atom of zinc to be bound to the protein to function properly. In polluted environments with an excess of copper or silver (note that these two elements are from the same family in the periodic table ) in the water, these ions will bind to the sodium-potassium transporter, kicking the zinc off of the binding site and rendering the pump useless. 

If the fish survives the initial influx of transition metal ions, it may be able to undergo acclimatory responses that will reduce the giU uptake of transition metals. This can occur by decreasing the rates of metal influx into the giU cells. The fish can also alter the production of metallothioneins, thereby tying up the toxic metal ions before they can bind to the transporter proteins. The fish wiU live if the flow of the metal ions can be attenuated enough to allow the sodium-potassium and the calcium-magnesium pumps to continue to function. The fish dies if the metal influx overwhelms the cellular defenses, binds to the pumps, and reduces their performance. 

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