Molecule disruption

The graphite lattice may show stacking faults or defects within the sheets, and, possibly, bending of the sheets (Fig. 2.25). Omission of a carbon atom (voids), or inclusions of noncarbon elements or molecules, disrupts the orderly configuration and inhibits crystallization of carbon as graphite. These impurities act as sites of local strain that directly influence crystallite size, distribution, and orientation within a sample, and in turn affect the physical and chemical characteristics of the material, especially its strength. 

The effects of exposure of organic solids to particular solvents such as pyridine on their conformational stability can also be Interpreted In terms of the structural features discussed above. How small nucleophilic molecules disrupt Inter- and Intramolecular polar Interactions In coals thereby relaxing the structural matrix and allowing further solvent penetration has been extensively discussed by Peppas (e.g. 11,12), Larsen (1,13) and Marzec (14-16) and their colleagues. Indeed the extent to which exposure to a polar solvent such as pyridine destabilizes a material s molecular structure Is a measure of the extent to which the stability of the material depends on polar Interactions. 

Temperature. The range of temperature over which proteins are soluble depends on their source. Typically the solubility of globular proteins increases with temperature up to a maximum. Above this critical temperature, thermal agitation within the molecule disrupts the tertiary structure and gives rise to denaturation. In enzymes this behaviour is paralleled to some extent by changes in activity. 

There is considerable support for the hypothesis that a molecule decomposes unimolecularly when a sufficient amount of energy becomes localized in a particular bond or mode of vibration.19 Knowing these various types of vibration as in the ethyl bromide molecule one is tempted to speculate as to which are the most likely ones to be involved in the chemical reaction. For example, if ethyl bromide decomposes to give a free ethyl radical and a bromine atom as the first step the action must occur by increasing the amplitude of vibration of the fundamental frequency Fi to the point of rupture. On the other hand if the molecule disrupts into ethylene and hydrobromic acid in a single internal operation the fundamental frequency Fq or F8 must be involved. These latter... 

While it is clear that the action of F on plant metabolism is complex and involves a variety of enzymes, the mode of action of F- ion on these enzymes is not so clear. The principal mechanisms that have been suggested include (1) formation of complexes with metalloenzymes, (2) removal of a metal cofactor from an enzyme system, and (3) binding to the free enzyme or to the enzyme substrate complex (Miller et al. 1983). Studies using a model system indicate that F can disrupt the hydrogen bonding of protein molecules (Edwards et al. 1984). Because hydrogen bonding is important in the maintenance of the tertiary structure of a protein molecule, disruption of an enzyme protein by F would result in enzyme inhibition. 

The presence of dissolved gas is essential for cavitation to occur in a liquid. The dissolved gas molecules disrupt intermolecular bonding between solvent molecules and hence, serve as nucleation sites for cavitation. There are three properties of dissolved gases that have significant influence on the degree of nucleation and cavitational intensity solubility of gas in the liquid, ratio of specific heats (y or Cp/Cy), and thermal conductivity (2). More soluble gases reduce the cavitational effects because the bubbles formed redissolve... 

Figure 4 Solvation properties of water as a function of temperature at 250 bar. Note that as water is heated from ambient, the dielectric constant drops off more rapidly than the density. This reflects the fact that the water molecules are still relatively close together, while the thermal motion of the molecules disrupts the alignment of the dipoles...

Detergents. These amphipathic molecules disrupt hydrophobic interactions, causing proteins to unfold into extended polypeptide chains. (Amphipathic molecules contain both hydrophobic and hydrophilic components.)... 

Higueruelo AP et al (2009) Atomic interactions and profile of small molecules disrupting protein-protein interfaces the TIMBAL database. Chem Biol Drug Des 74(5) 457 167... 

The influence of adsorbed proteins on interfacial viscosity is relevant to the fluidity of biological membranes. An unusual effect is observed when lipid molecules are incorporated into protein monolayers, first reported by Schulman and Rideal As the mixed film is compressed, T] increases normally but then goes through a maximum, thereafter decreasing sharply with further increase of 11(6). Evidently, above a certain surface density, lipid molecules disrupt interactions between protein chains. The... 

That brings us to carbon dioxide, methane, and water. These gases do absorb infrared radiation because certain stretches and bends of the bonds in these molecules disrupt the electron distribution in ways necessary for IR absorption. Because carbon dioxide, water vapor, and methane are three molecules that are capable of absorbing IR radiation, these molecules play a major role in keeping Earth warm. 

For intact coatings, the major deterioration mechanism is the transport of electrolyte solutions to the interface between the steel substrate and the coating. This transport results from the equalization of concentration and temperature differences. Water molecules disrupt the bonding and polar interactions that are responsible for a good adhesion at the interface [86]. Underfilm corrosion is possible because of the loss of adhesion. The coatings have been defined as intact when the potential of the steel panel was not measurable at the beginning of the test. 

Wahl, R.C., Zhang, J., Uoyd, D.L., Hale, C, and St. Jean, D.J. Jr. (2014) Small molecule disrupters of the glucokinase-glucokinase regulatory protein interaction 1. 

Small molecule disrupters of the Rb-Raf-1 protein-protein interaction Tumor growth inhibitors... 

Dephasing is another important broadening process for spectral lines of adsorbates. Elastic collisions of phonons and conduction electrons with adsorbed atoms or molecules disrupt the phases of their induced dipole moments and thus provide surface-specific pathways for phase relaxation. If an adsorbed particle can be considered as a two-level system, both the lifetime of its excited state, T, and the dephasing time, T, contribute to the spectral linewidth 7 as ... 

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