Effect first salt

Effect of salt type and concentration The ionic strength of the aqueous solution in eontaet with a reverse micelle phase affects protein partitioning in a number of ways [18,23]. The first is through modification of electrostatic interactions between the protein surface and the surfaetant head groups by modifieation of the eleetrieal double layers adjacent to both the eharged inner mieelle wall and the protein surface. The second effect is to salt out the protein from the mieelle phase because of the inereased propensity of the ionie speeies to migrate to the micelle water pool, reduee the size of the reverse mieelles, and thus displace the protein. 

The pH of a solution of an acid salt is determined by two effects first, hydrolysis, and second, the dissociation of the hydrogen-containing anion to produce hydrogen ion. In the case of NaHSOg discussed above, the second effect is the greater, and the solution is acidic. For NaHCOg, with Kh oo = 4.3 x 10 (weak) and Kbco - = 4.7 X 10 (very weak), the effect of hydrolysis is the greater, and the solution is basic. 

Another important effect is the decrease in solubility of a salt because of the presence of another salt which has a common ion with the first salt. For example, it is found by experiment that 9.9 g of lead chloride, PbCl., will dissolve in i liter of water at 20" but that only 0.05 g of lead chloride will dissolve in a liter of water containing 1 gfw of potassium chloride in solution. Thus the presence of the potassium chloride reduces the solubility of lead chloride to less than 1 percent of its value in pure water. This effect is especially striking when it is remembered that most other salts, such as lead sulfate, PbS04, have the same solubility, to within 5 or 10 percent, in a 1 F solution of potassium chloride as in pure water. 

Shimizu and Oku (1957) studied the effects of salts on the solubility of wool in 0.1 M KOH. At low salt concentrations the effects of various ions followed the Hofmeister series. Similarly, McPhee (1958b, 1959) has shown that whereas 56 % of wool was dissolved by 1.286 N NaOH at 25°C in 2 hr, only 2 % dissolved when the solution was first saturated with NaCl. There was a corresponding decrease in formation of primary amino groups and in loss of cystine. Not all salts were equally effective in protecting wool against alkali damage. The effectiveness of 2 M solutions of the sodium salts decreased in the order 8203 > SO3 > citrate > COs" > SO 4 > acetate > Cl > Br > NOs" > I > CNS . Cations followed the order Li+, Na+ > K+. Similar rates of alkali uptake were obtained with all salts at a concentration oi 2 M. 

Several factors affect the salt sensitivity of plants. We first evaluated the effect of light intensity on the salt-stress. Figure 2 clearly showed that tobacco seedlings were more severely affected by salt stress under high light intensity both on the basis of chlorophyll content and fresh wei t increase. This result indicated that light, probably photosynthetic process, would be involved in the salt-stress. To characterize the salt-stress mechanism, we examine the effect of salt on the photosynthetic activities of isolated thylakoid membranes. Previously, we reported that the presence of salt in assay inhibited the photosystem II activity of tobacco thylakoid membranes but not photosystem I activities (Murota et al., 1994). Then, we further examined the effect of salt on the irreversible photodamage of thylakoid membrane activity. 

In section 5.2.3 we discussed the effect of salts on the solubility of organic electrolytes. The parabolic effects of salts on protein solubility (Fig. 11.6) might, at first sight, seem unexpected. Data, produced over 70 years ago, on haemoglobin solubility (Fig. 11.6b) shows a general increase in solubility with increasing ionic strength of salts such as NaCl, KCl and... 

The work of Robinson and Wilke [469] was probably the first one which quantitatively investigated the effect of salts on gassing of liquids. The ionic strength was established as an influence quantity, which was calculated as follows I = 0.5 52 2 Wi [g-ion/1] all ions have therefore to be taken into consideration, (zj is the charge number of an ion i and m is its molality.)... 

The addition of electrolytes to a solution decreases the viscosity of a fresh polymer solution as will be discussed in the next section. High temperatures less than the thermodegrading conditions (less than 70-100°C depending on the polymer) cause a drop in the viscosity. This is also a reversible change associated with the change in the conformation of the chains in solution. The temperature effect on solution viscosity will be discussed. The effects of salt, temperature, severe shear, and aging will be discussed from the standpoint of viscosities and chain conformations in solution. First of all, the factors causing temporary viscosity losses will be presented. 

The effect of salt concentration (sodium perchlorate) on the decay rate of Cl2" transient in the presence of 10"3M Fe2+ was examined. A marked salt effect was observed, the pseudo first order rate constant being reduced from 3.8 X 104 sec."1 at ionic strength 0.04, to 2.5 X 104 sec."1 at ionic strength 0.25. Reaction 3 would be expected to show a negative salt effect, but the observed decrease in rate constant with increasing ionic strength is somewhat less than expected. 

The various procedures used to differentiate the albumoses and the peptones are all based on the method of fractional precipitation. Before considering how the course of hydrolysis by pepsin is effected, and in order to be able to follow all the changes that occur, it is necessary first to consider various reagents utilized for this study. We will first examine the effect of salts. 

Ihe dependence on ion strength is called first salt effect. Its substance is the change in reaction rate due to addition to the solution of neutral outside salt, whose ions do not participate in reactions. This effect is only due to an increase in ion strength and may be expressed in the Bronsted-Bjerrum equation, which in logarithmic form looks as follows... 

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