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  2. Chemical polarity - Wikipedia

    en.wikipedia.org/wiki/Chemical_polarity

    The terms "polar" and "nonpolar" are usually applied to covalent bonds, that is, bonds where the polarity is not complete. To determine the polarity of a covalent bond using numerical means, the difference between the electronegativity of the atoms is used.

  3. Beta barrel - Wikipedia

    en.wikipedia.org/wiki/Beta_barrel

    The arrows indicate the hydrogen bonds that were identified in the figures. The relative direction of each strand is indicated by the "+" and "-" at the bottom of the table. Except for strands 1 and 6, all strands are antiparallel. The parallel interaction between strands 1 and 6 accounts for the different appearance of the hydrogen bonding ...

  4. Membrane lipid - Wikipedia

    en.wikipedia.org/wiki/Membrane_lipid

    Lipids are amphiphilic: they have one end that is soluble in water ('polar') and an ending that is soluble in fat ('nonpolar'). By forming a double layer with the polar ends pointing outwards and the nonpolar ends pointing inwards membrane lipids can form a 'lipid bilayer' which keeps the watery interior of the cell separate from the watery ...

  5. Hydrophobic collapse - Wikipedia

    en.wikipedia.org/wiki/Hydrophobic_collapse

    Hydrophobic collapse is a proposed process for the production of the 3-D conformation adopted by polypeptides and other molecules in polar solvents. The theory states that the nascent polypeptide forms initial secondary structure (ɑ-helices and β-strands) creating localized regions of predominantly hydrophobic residues.

  6. Chemical structure - Wikipedia

    en.wikipedia.org/wiki/Chemical_structure

    Theories of chemical structure were first developed by August Kekulé, Archibald Scott Couper, and Aleksandr Butlerov, among others, from about 1858. [4] These theories were first to state that chemical compounds are not a random cluster of atoms and functional groups, but rather had a definite order defined by the valency of the atoms composing the molecule, giving the molecules a three ...

  7. Ammonium lauryl sulfate - Wikipedia

    en.wikipedia.org/wiki/Ammonium_lauryl_sulfate

    Above the critical micelle concentration, the anions organize into a micelle, in which they form a sphere with the polar, hydrophilic heads of the sulfate portion on the outside (surface) of the sphere and the nonpolar, hydrophobic tails pointing inwards towards the center. The water molecules around the micelle in turn arrange themselves ...

  8. Energy profile (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Energy_profile_(chemistry)

    In other words, the energy difference between the polar and non-polar solvent is greater for the ground state (for the starting material) than in the transition state. Figure 11: Shows the effects that solvent polarity has on an S N 2 mechanism. The polar solvent is shown in red and the non-polar solvent is shown in blue

  9. Hydrophobic effect - Wikipedia

    en.wikipedia.org/wiki/Hydrophobic_effect

    The hydrophobic effect was found to be entropy-driven at room temperature because of the reduced mobility of water molecules in the solvation shell of the non-polar solute; however, the enthalpic component of transfer energy was found to be favorable, meaning it strengthened water-water hydrogen bonds in the solvation shell due to the reduced ...