Nonpolar schematic representation

Figure 18-5 Schematic representation of (a) a membrane lipid, (b) a bilayer structure formed by lipid molecules in polar media the interior of the bilayer is nonpolar, and (c) a continuous bilayer structure (liposome) with polar interior and exterior...

Fig. 5. Schematic representation of HZSM-5 porous structure (a) and of molecules of butyl alcohol, of reaction intermediates, and of products in HZSM-5 pores (b) polar and nonpolar fragments of the molecules are shown as white and dashed areas, respectively.

Figure 9 (A) Schematic representation of the mode] of Rhizopus lipase. The arrow indicate tie helical Hri covering [he active site. (B) Represcn ration of iius atomic simetinu of the Rhizppus lipase drawn with the Yin der Weals radii. Hie view is the same as that of A. The nonpolar residues arc shaded.

Figure 2. Schematic representation of inhomogeneous broadening and relative energy levels of and Lb states (a) under vacuum, (b) in nonpolar hydrocarbon solvent, (c) in polar water at the instant of absorption, and (d) in polar water after certain-time solvation [55],...

Figure 12. Schematic representation of the five elemental structures used by Jonsson and Wennerstrom [18] (a) spherical, (b) cylindrical, (c) lamellar, (d) inverted cylindrical, and (e) inverted spherical. Nonpolar regions are crosshatched.

Figure 3.1 Schematic representations of a) a water molecule orientation near a nonpolar CHs-group, which is optimal if none of the hydrogen atoms or electron pairs is directed toward the nonpolar group ( = 0) b) contour line diagrams of three polar molecules with the first inner line of a solvation energy o/O kcal/mol, the second line of 1 kcal, the third line of 2 kcal/mol e/c and c) of the hydrophobic effect. Upon association of hydrophobic particles water or other solvent molecules are released. Entropy grows.

Fig. 5-1. Schematic representation of the equilibrium system in ion-pair chromatography on nonpolar stationary phases with lipophilic ions in the mobile phase.

Studies in recent years on the surface properties of transition metal oxides have demonstrated that the surface structural stability, the surface electronic structure, and the surface chemical reactivity depend on the crystallographic orientation of the exposed surface and the presence of surface imperfection, such as steps and point defects (1 ). ZnO is one recent example. The natural surfaces of ZnO, which can be prepared in a relatively well-ordered state, include he Zn-polar (0001), the 0-polar (OOOT), and the nonpolar (IOIO) surfaces. (See Figure 1 for a schematic representation of these surfaces). These surfaces have been shown to possess different chemisorptive properties and reactivities. It was shown that CO2 was desorbed from a nonpolar surface at about 120 0, but from a Zn-polar surface at (2 ). 

A convenient way to describe microemulsions is to compare them with micelles. The latter, which are thermodynamically stable, may consist of spherical units with a radius that is usually less than 5 nm. Two types of micelles may be considered (i) normal micelles in which the hydrocarbon tails form the core and the polar head groups are in contact with the aqueous medium and (ii) reverse micelles (formed in nonpolar media) in which the water core contains the polar head groups and the hydrocarbon tails are now in contact with the oil. Normal micelles can solubiHse oil in the hydrocarbon core to form O/W microemulsions, whereas reverse micelles can solubilise water to form a W/O microemulsion. A schematic representation of these systems is shown in Figure 15.1. 

The high resolution X-ray structural studies of the native enzyme, the enzyme-ADPR binary complex, and the enzyme-o-phenanthroline binary complex (47) have revealed that the active site zinc ion is located some 20 A below the surface of the protein at the point of convergence of two deep clefts (see the schematic representation in Fig. 6). One of these clefts has been identified as the coenzyme binding cleft (47). This cleft extends from the surface of the subunit to the zinc ion. If a model of NADH is fit to the coordinates of the ADPR binding site, then the nicotinamide ring can be oriented in such a way that it fits into a pocket adjacent to the zinc ion (47). The second deep cleft, or channel, also extends from the surface of the subunit down to the zinc ion. The inner surface of this cleft is made up of nonpolar amino acid residues contributed by both subunits. 

Fig. 15. Schematic representation of the physical and chemical states of lipids in intestinal content during fat digestion and absorption. An oil phase composed of higher glyceride and some nonionized fatty acid is in equilibrium with an aqueous micellar phase of bile acid, monoglyceride, nonionized fatty acids, and fatty acid soaps. Nonpolar lipids—e.g., fat-soluble vitamins,...

The amphiphilic character of surfactant molecules is due to the association of two parts with very differing polarities inside the same molecule [2]. One part is highly nonpolar, hydrophobic or lipophilic, usually an alkyl chain. Another part of the surfactant molecule is polar or hydrophilic. It can be a nonionic chain with polar groups, such as ether, alcohol or amine groups, or an ionic (anionic or cationic) group. Figure 2.1 shows the schematic representation of a surfectant molecule. Some surfactants have two nonpolar tails or two polar heads, as illustrated in the figure. The nature of the surfactant polar head is used to classify the molecules. 

Fig. 6. Schematic representation of possible phase diagrams for binary mixtures the shaded areas indicate two phase regions (a) upper critical solution temperature behavior (UCST) (b) lower critical solution temperature behavior (LOST) (c) combination of LOST and UCST, mostly observed in nonpolar polymer solutions (d) phase diagram showing upper, lower, and quasilower critical phase boundaries (e) immiscibility loop and (f) hourglass-shaped phase boundary obtained by convergence of upper and lower critical boundaries.

Figure 4 Schematic representation of a retention cycie pathway for the conformational interconversion of a globular protein or polypeptide, Pn.m> fi" solution in the mobile phase and in two unfolded states, and Pus> which occur in the presence of a liquid-solid interface involving immobilized nonpolar ligands of an RPC or HIC sorbent in the presence of an aquo-organic solvent, a kosmotropic or a chaotropic mobile phase system. If the globular protein or polypeptide undergoes a two-stage interconversion in the mobile phase and at the surface, the corresponding distribution process between the two chromatographic phases will involve the unfolded intermediates, Pum and PJjs- Also shown are the corresponding rate constants, k, for these interconversions. The subscripts refer to the native and unfolded states, N and U, respectively, and the mobile and stationary phase, M and S, respectively.

FIGURE 19.5 Schematic representation of phospholipids and giycolipids The green circle represents the polar part of the molecule, and the tails represent the nonpolar hydrocarbon chains. Question If this molecule were placed in water, how do you think it might orient itself at the surface ... 

Figure 35 Schematic representation of the nanopartides (NPs) studied in this work. Top panel represents homogeneous NPs, while bottom panel represents Janus NPs. Purple (gray In the print version) and green (light gray in the print version) spheres are nonpolar and polar beads, respectively. Figure taken from Luu et al (2013a, 2013b).

Microheterogeneous environments, such as those found in reverse micelles (RMs) and microemulsions, have tremendous promise because of the nonstandard environments they present. Often, chemistries that occur in these solutions do not occur in homogeneous liquid solutions [1-4]. Essentially, RMs are spatially ordered macromolecular assemblies of surfactants formed in nonpolar solvents, in which the polar head groups of the surfactants point inward toward a polar core and the hydrocarbon chains point outward toward the nonpolar medium [5, 6] (see schematic representation in Fig. 14.1). 

Figure 14.1 Schematic representation of the RMs. (1) Polar pool, (2) interface, and (3) nonpolar pseudophase.

The following designations are accepted in the schematic representation of light polarization in physics literature (Figure 6.21). The plane of oscillations of the vector E is set by arrows. The polarized beam is represented accordingly by a number of parallel arrows. If the plane of oscillations is perpendicular to the drawing plane, arrows are projected in points. A nonpolarized beam is represented by alternate points and arrows. 

Fig. 2-13. Schematic two-dimensional representation of the solubilization of (b) n-nonane as a nonpolar substrate, and (c) 1-pentanol as another amphiphile, by a spherical ionic micelle (a) of an -decanoic acid salt in water.

---