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A phonon is a collective excitation in a periodic, elastic arrangement of atoms or molecules in condensed matter, specifically in solids and some liquids.A type of quasiparticle in physics, [1] a phonon is an excited state in the quantum mechanical quantization of the modes of vibrations for elastic structures of interacting particles.
Phosphatidylcholine is a major constituent of cell membranes and pulmonary surfactant, and is more commonly found in the exoplasmic or outer leaflet of a cell membrane. It is thought to be transported between membranes within the cell by phosphatidylcholine transfer protein (PCTP). [3]
The solution to this gives the atomic displacement due to the phonon, which is given by ,,, = (),, (,) [(,)] where the atomic position i is described by l, m, and κ, which represent the specific atomic layer, l, the particular unit cell it is in, m, and the position of the atom with respect to its own unit cell, κ. The term x(l,m) is the ...
The term "chiral" in general is used to describe the object that is non-superposable on its mirror image. [18] In chemistry, chirality usually refers to molecules. Two mirror images of a chiral molecule are called enantiomers or optical isomers. Pairs of enantiomers are often designated as "right-", "left-handed" or, if they have no bias ...
A chiral phenomenon is one that is not identical to its mirror image (see the article on mathematical chirality). The spin of a particle may be used to define a handedness, or helicity, for that particle, which, in the case of a massless particle, is the same as chirality. A symmetry transformation between the two is called parity transformation.
Chirality with hands and two enantiomers of a generic amino acid The direction of current flow and induced magnetic flux follow a "handness" relationship. The term chiral / ˈ k aɪ r əl / describes an object, especially a molecule, which has or produces a non-superposable mirror image of itself.
The nearest neighbors of a chloride ion are six mercury ions, at two somewhat different distances. A diagram can be seen on line, with blue balls representing mercury, green chlorine, and yellow sulfur. [7] Various sulfide halides of Hg share the feature of being face-sharing [HgS 2 X 4] −6 polyhedral, with X=Cl in the case of corderoite.
Cell membranes require high levels of cholesterol – typically an average of 20% cholesterol in the whole membrane, increasing locally in raft areas up to 50% cholesterol (- % is molecular ratio). [6] It associates preferentially with sphingolipids (see diagram) in cholesterol-rich lipid rafts areas of the membranes in eukaryotic cells. [7]