Essentiality calcium

Match Tand Kobayashi M (1998) Boron and calcium, essential inorganic constituents of pectin polysaccharides in higher plant cell walls. J Plant Res 111 179-190. 

The salt-like carbides. Among these are aluminium tricarbide imethanide) AI4C3 (containing essentially C ions) in the crystal lattice and the rather more common dicarbides containing the C ion, for example calcium dicarbide CaCjt these carbides are hydrolysed by water yielding methane and ethyne respectively ... 

Phosphorus, like nitrogen, is an essential constituent of living matter where it may be partly in combination (as phosphate groups) with organic groups, for example in lecithin and egg yolk, or mainly in inorganic form, as calcium phosphate(V), in bones and teeth. 

Deliquescence and efflorescence. A substance is said to deliquesce (Latin to become liquid) when it forms a solution or liquid phase upon standing in the air. The essential condition is that the vapour pressure of the saturated solution of the highest hydrate at the ordinary temperature should be less than the partial pressure of the aqueous vapour in the atmosphere. Water will be absorbed by the substance, which gradually liquefies to a saturated solution water vapour will continue to be absorbed by the latter until an unsaturated solution, having the same vapour pressure as the partial pressure of water vapour in the air, is formed. In order that the vapour pressure of the saturated solution may be sufficiently low, the substance must be extremely soluble in water, and it is only such substances (e.g., calcium chloride, zinc chloride and potassium hydroxide) that deliquesce. 

Iodine monochlorlde may be prepared as follows. Pass dry chlorine into 127 g. of iodine contained in a 125 ml. distilling flask until the weight has increased by 34-6 g. The chlorine should be led in at or below the surface of the iodine whilst the flask is gently shaken it is essential to have an excess of iodine. Distil the iodine chloride in an ordinary distillation apparatus use a filter flask, protected from atmospheric moisture by a calcium chloride (or cotton wool) guard tube, as a receiver. Collect the fraction b.p. 97-105° the jdeld is 140 g. Preserve the iodine monochloride in a dry, glass-stoppered bottle. 

White phosphorus may be made by several methods. By one process, tri-calcium phosphate, the essential ingredient of phosphate rock, is heated in the presence of carbon and silica in an electric furnace or fuel-fired furnace. Elementary phosphorus is liberated as vapor and may be collected under phosphoric acid, an important compound in making super-phosphate fertilizers. 

Calcium is a metallic element, fifth in abundance in the earth s crust, of which if forms more than 3%. It is an essential constituent of leaves, bones, teeth, and shells. Never found in nature uncombined, it occurs abundantly as limestone, gypsum, and fluorite. Apatite is the fluorophosphate or chlorophosphate of calcium. 

One method for measuring the temperature of the sea is to measure this ratio. Of course, if you were to do it now, you would take a thermometer and not a mass spectrometer. But how do you determine the temperature of the sea as it was 10,000 years ago The answer lies with tiny sea creatures called diatoms. These have shells made from calcium carbonate, itself derived from carbon dioxide in sea water. As the diatoms die, they fall to the sea floor and build a sediment of calcium carbonate. If a sample is taken from a layer of sediment 10,000 years old, the carbon dioxide can be released by addition of acid. If this carbon dioxide is put into a suitable mass spectrometer, the ratio of carbon isotopes can be measured accurately. From this value and the graph of solubilities of isotopic forms of carbon dioxide with temperature (Figure 46.5), a temperature can be extrapolated. This is the temperature of the sea during the time the diatoms were alive. To conduct such experiments in a significant manner, it is essential that the isotope abundance ratios be measured very accurately. 

Some commonly used primary nutrient fertilizers are incidentally also rich sources of calcium. Ordinary superphosphate contains monocalcium phosphate and gypsum in amounts equivalent to all of the calcium originally present in the phosphate rock. Triple superphosphate contains soluble monocalcium phosphate equivalent to essentially all the P2 5 product. Other fertilizers rich in calcium are calcium nitrate [10124-37-5] calcium ammonium nitrate [39368-85-9] and calcium cyanamide [156-62-7]. The popular ammonium phosphate-based fertilizers are essentially devoid of calcium, but, in view of the natural calcium content of soils, this does not appear to be a problem. 

The FCC is to food-additive chemicals what the USP—NF is to dmgs. In fact, many chemicals that are used in dmgs also are food additives (qv) and thus may have monographs in both the USP—NF and in the FCC. Examples of food-additive chemicals are ascorbic acid [50-81-7] (see Vitamins), butylated hydroxytoluene [128-37-0] (BHT) (see Antioxidants), calcium chloride [10043-52-4] (see Calcium compounds), ethyl vanillin [121-32-4] (see Vanillin), ferrous fumarate [7705-12-6] and ferrous sulfate [7720-78-7] (see Iron compounds), niacin [59-67-6] sodium chloride [7647-14-5] sodium hydroxide [1310-73-2] (see lkaliand cm ORiNE products), sodium phosphate dibasic [7558-79-4] (see Phosphoric acids and phosphates), spearmint oil [8008-79-5] (see Oils, essential), tartaric acid [133-37-9] (see Hydroxy dicarboxylic acids), tragacanth [9000-65-1] (see Gums), and vitamin A [11103-57-4]. 

Magnesium ion is essential for normal Ca " and K" metaboHsm. In acute experimental magnesium deficiency in humans, hypocalcemia occurs despite adequate calcium intake and absorption and despite normal renal and parathyroid functions. Negative K" balance is also observed. AH biochemical and clinical abnormaHties disappear upon restoration of adequate amounts of magnesium to the diet (64). 

Many plants outside of North America pfill or granulate a mixture of ammonium nitrate and calcium carbonate. Production of this mixture, often called calcium ammonium nitrate, essentially removes any explosion hazard. In many cases calcium nitrate recovered from acidulation of phosphate rock (see Phosphoric acid and the phosphates) is reacted with ammonia and carbon dioxide to give a calcium carbonate—ammonium nitrate mixture containing 21 to 26% nitrogen (23). 

ThermalLkjucfaction Process. In the thermal Hquefaction process (see Eig. 1), a starch slurry containing no enzyme or added calcium is heated for several minutes. The slurry is slightly acidic and sufficient acid Hquefaction is achieved to reduce viscosity. The hydrolyzate (at essentially zero DE) is flash-cooled to 95—100°C, a-amylase is added, and the pH is adjusted. The reaction then goes to completion. 

The main role of the human thyroid gland is production of thyroid hormones (iodinated amino acids), essential for adequate growth, development, and energy metaboHsm (1 6). Thyroid underfunction is an occurrence that can be treated successfully with thyroid preparations. In addition, the thyroid secretes calcitonin (also known as thyrocalcitonin), a polypeptide that lowers excessively high calcium blood levels. Thyroid hyperfunction, another important clinical entity, can be corrected by treatment with a variety of substances known as antithyroid dmgs. 

Disease States. Rickets is the most common disease associated with vitamin D deficiency. Many other disease states have been shown to be related to vitamin D. These can iavolve a lack of the vitamin, deficient synthesis of the metaboUtes from the vitamin, deficient control mechanisms, or defective organ receptors. The control of calcium and phosphoms is essential ia the maintenance of normal cellular biochemistry, eg, muscle contraction, nerve conduction, and enzyme function. The vitamin D metaboUtes also have a function ia cell proliferation. They iateract with other factors and receptors to regulate gene transcription. 

Chlorine. Nearly all chlorine compounds are readily soluble in water. As a result, the major reservoir for this element in Figure 1 is the ocean (5). Chloride, as noted earHer, is naturally present at low levels in rain and snow, especially over and near the oceans. Widespread increases in chloride concentration in mnoff in much of the United States can be attributed to the extensive use of sodium chloride and calcium chloride for deicing of streets and highways. Ref. 19 points out the importance of the increased use of deicing salt as a cause of increased chloride concentrations in streams of the northeastern United States and the role of this factor in the chloride trends in Lake Ontario. Increases in chloride concentration also can occur as a result of disposal of sewage, oil field brines, and various kinds of industrial waste. Thus, chloride concentration trends also can be considered as an index of the alternation of streamwater chemistry by human development in the industrialized sections of the world. Although chlorine is an essential element for animal nutrition, it is of less importance for other life forms. 

Factor IV. Calcium ion, although essential, is required in only trace amounts for physiologic coagulation. Before such a decreased level could be attained, many other calcium-dependent body functions, such as myocardial contractihty, would fail and death would ensue. 

The oceans contain vast quantities of ionic calcium,, to the extent of 400 mg/L of seawater (3). Calcium is present ia living organisms as a constituent of bones, teeth, shell, and coral. It is essential to plant as well as animal life. 

The Ca(Il) coaceatratioa ia blood is closely coatroUed aormal values He betweea 2.1 and 2.6 mmol/L (8.5—10.4 mg/dL) of semm (21). The free calcium ion concentration is near 1.2 mmol/L the rest is chelated with blood proteias or, to a lesser extent, with citrate. It is the free Ca(Il) ia the semm that determines the calcium balance with the tissues. The mineral phase of bone is essentially ia chemical equiUbrium with calcium and phosphate ions present ia blood semm, and bone cells can easily promote either the deposition or dissolution of the mineral phase by localized changes ia pH or chelating... 

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