Ca2 + , Calcium ions

CaC03(s) Calcium carbonate (limestone) - Precipitation- Ca2+ Calcium ion dissolution reactions + CO - Carbonate ion -8.3b 11.6... 

Four of the main-group cations are essential in human nutrition (Table A). Of these, the most important is Ca2+. About 90% of the calcium in the body is found in bones and teeth, largely in the form of hydroxyapatite, CatOH)2 - SCa PO. Calcium ions in bones and teeth exchange readily with those in the blood about 0.6 g of Ca2+ enters and leaves your bones every day. In a normal adult this exchange is in balance, but in elderly people, particularly women, there is sometimes a net loss of bone calcium, leading to the disease known as osteoporosis. 

The slope of 2.0 was also reported by Azzi and Chance (1969), Ashley (1970), and Baker et al. (1971), although several values between 2.0 and 4.0 were also reported by other investigators. The slope of 2 indicates that one aequorin molecule needs to be bound with two Ca2+ for the emission of light to take place the requirement of two Ca2+ was confirmed later by the titration of aequorin with calcium ions (Shimomura, 1995c Shimomura and Inouye, 1996). In Fig. 4.1.7,... 

Binding calcium ions (Ca2+) is a prerequisite for the activation of seven clotting factors in the coagulation cascade that are dependent on vitamin K. The term cascade indicates, that the factois involved depend from... 

LAS is moderately sensitive to water hardness such that at certain concentration levels governed by the solubility product (Ksp) and the CMC, Ca(LAS)2 will precipitate out of solution [26]. The precipitation boundary diagram provides a useful method to study the interaction of LAS with calcium ions. From this diagram, approximate values of the CMC and Ksp for LAS and Ca2+ can be approximated [27]. 

Soaps are composed of sodium salts of various fatty acids. These acids include those with the general structure CH3-(CH2) -COOH where n = 6 (caprylic acid), 8 (capric acid), 10 (lauric acid), 12 (myristic acid), 14 (palmitic acid), and 16 (stearic acid). Oleic acid (CH3-(CH2)7-CH=CH-(CH2)7-COOH) and linoleic acid (CH3-(CH2)4-CH=CH- H2-CH=CH-(CH2)7-COOH) are also common soap ingredients. These sodium salts readily dissolve in water, but other metal ions such as Ca2+ and Mg2+ form precipitates with the fatty acid anions. For example, the dissolution of the sodium salt of lauric acid and the subsequent formation of a precipitate of the lauric acid anion with calcium ion is given by... 

The binding of calcium ion to calmodulin, a major biochemical regulator of ion pumps and receptors, occurs on a time scale about a thousand times shorter than that observed for RNA conformational change. This Ca2+-calmodulin binding, which can be followed successfully by nuclear magnetic resonance (NMR), occurs in about ten milliseconds. 

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