Chemistry Assignment (Solved)

Added on - Apr 2020

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Running head: CHEMISTRY 0CHEMISTRYName of StudentInstitution Affiliation
CHEMISTRY2IntroductionIt is very difficult to study complex natural cell membrane due to their native states.Lipids with the simpler model system are hence admirable for studying biomolecule interactionas well as the particular role of the component of the membrane. The suitable choice of themodel will highly depend on the method employed for the scrutiny[ CITATION Ang15 \l 1033 ].Everymodel selected will have both disadvantage and advantage. The bilayers of lipids can bemade on the solid support through using multiple methods including Langmuir-Blodgett (LB)and LS (Langmuir –Scaefer ). This method can be done in situ but LS and LB methods will needdeposition of just a monolayer at a time by the help of Langmuir fil balance. This method ispreferred for the bilayer deposition having a specific and controlled asymmetric leafletcomposition.The most common method of preparing model cellular membrane is (DIBB) DropletInterface Bilayer method. In this technique, the lipid bilayer is made from two water dropletswhich are submerged in oil and also coated with a monolayer of lipids. This can be eithercontrol, asymmetric or symmetric each droplet composition bilayer tailoring can berealized[ CITATION Jac12 \l 1033 ].In addition, the solution on either side of the membrane is ableto be controlled permitting for studies of the interactions in the membrane and specificbimolecular. This technique was employed recently to reconstitute bilayer of lipids from the totalextract of model cell membrane known asEscharia coli.SURFACE SENSITIVE METHODS TO STUDYSUPPORTED LIPID BILAYERS AND MOLECULARINTERACTIONS WITH THEM
CHEMISTRY31.Quartz crystal microbalance with dissipation.The inherent properties of the piezoelectric quartz can be keenly analyzed using QCM-D totrigger oscillation in the sensor, this will respond by deforming immediately when an externalvoltage is subjected to it[ CITATION Bud12 \l 1033 ].The standing shear waves will be developed inthe two gold electrodes due to the application of the alternating voltage. The shear wave willdecay into the liquid having the characteristic length of decay. This length is always taken as250nm, this for the crystal which is immersed in a pure water hence, this will give a perfectrange of detection for the QCM-D. A solvent will be identified as a mass which is coupled witha mean thickness conforming to ΔῥL. Where ῥL is taken as the density of the liquid. The lengthof decay will vary with the following equation[ CITATION Gün11 \l 1033 ].nL; wherenL is the absolute density of the liquid.Hence, if the solvent is exchanged with another one having higher viscosity, it willtrigger an increase in the mean thickness detected by the crystal. The principle for the operationof QCM.D is based on the relationship between the change in frequency and the change in massof sensor crystal. For such setup, if a change in mass is taken as Δm and change in frequency istaken as Δf, then from the simple Sauerbrey relationship Δm=-C* Δf/n. where C is the materialspecific Saurbray constant which is given as C=tg*ῥq/f0 and n is the harmonic number. Tq is thethickness of the quartz while ῥq is the density of the quartz[ CITATION Vin14 \l 1033 ].QCM-D basically records the wet adsorbed and not the dry ones since other opticaltechniques like ellipsometry, reflectometry and surface plasmon will do. This can be evident asan asset of the QCM-D method because it includes a tool needed for complementary info for the
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