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1. Define amphipathic molecules on amino acid and suggest the relation of its characteristicsthat may bring forward interesting functions on enzymes. Suggest if enzymes can actually reallyacting as this molecule. Then try to suggest one application using this characteristic if you may.

I have copy paste one abstract to suggest the application, please read and make yourselfunderstanding the whole scenario. After this whole exercise, you MUST know to

define amphipathic molecules and be able to draw in a diagram the molecules. You mayuse any molecules with the same characteristic, it is not only restricted to the aminoacid.

Definition for amphipathic is pertains to a molecule containing bothpolar (water-soluble)

andnonpolar (not water-soluble) portions in its structure or relating to

a molecule havinghydrophobic andhydrophilic regions.Many biomolecules are

amphipathic:phospholipids,cholesterol,glycolipids,fatty acids, bile acids, saponins, etc. In

fact, it is the amphipathic nature ofphospholipids that they form bilayers incell membrane.

They position theirpolar groups towards the surroundingaqueous medium whereas

theirhydrophobic chains towards the inside of the bilayer, defining anonpolar region between

twopolar ones.

It has been suggested that amphiphilic amino acids play an important role in the adsorption of

proteins on nanostructured surfaces with an ordered, striped domain structure such as those

presented by monolayer-protected metal nanoparticles (MPMNs). We have proposed and

now further explore this hypothesis by studying the adsorption behaviour of proteins on

MPMN surfaces by molecular dynamics (MD) simulations. Our atomistic MD simulations oflysozyme (Lyz) on nanostructured surfaces, including single component surfaces and several

theoretical nanopatterns of different spacing, presented here confirm the special role of amino

acids containing sidechain amines in facilitating direct protein adsorption to MPMN surfaces.

While we have previously demonstrated that an amphiphilic amino acid lysine is responsible

for selective adsorption behaviour of Cyt C on nanostructured surfaces, in the case of Lyz it

is the amphipathic character of arginine that enables the protein to form close contacts with

both polar and non-polar surface ligands simultaneously. This renders it especially important

for interactions with surfaces composed of adjacent nano-scale chemical domains. Arg is also

capable of forming close contacts with homogeneous hydrophobic and hydrophilic ligand

surfaces. We have also found that other amphiphilic amino acids, such as tyrosine and

tryptophan, interact with surfaces viawater-mediated contacts. Bridging water molecules

adopt orientations which differ from those of simple surface-adsorbed waters, with the

specificity of their orientations facilitating the protein-surface contacts. Our findings suggest

that not only nanopatterned surfaces can be designed to selectively interact with different

proteins but proteins may be engineered to specifically interact with nanomaterials by

http://www.biology-online.org/dictionary/Polarhttp://www.biology-online.org/dictionary/Nonpolarhttp://www.biology-online.org/dictionary/Hydrophobichttp://www.biology-online.org/dictionary/Hydrophilichttp://www.biology-online.org/dictionary/Phospholipidshttp://www.biology-online.org/dictionary/Cholesterolhttp://www.biology-online.org/dictionary/Glycolipidshttp://www.biology-online.org/dictionary/Fatty_acidshttp://www.biology-online.org/dictionary/Phospholipidshttp://www.biology-online.org/dictionary/Cell_membranehttp://www.biology-online.org/dictionary/Polarhttp://www.biology-online.org/dictionary/Aqueoushttp://www.biology-online.org/dictionary/Hydrophobichttp://www.biology-online.org/dictionary/Nonpolarhttp://www.biology-online.org/dictionary/Polarhttp://www.biology-online.org/dictionary/Polarhttp://www.biology-online.org/dictionary/Nonpolarhttp://www.biology-online.org/dictionary/Hydrophobichttp://www.biology-online.org/dictionary/Aqueoushttp://www.biology-online.org/dictionary/Polarhttp://www.biology-online.org/dictionary/Cell_membranehttp://www.biology-online.org/dictionary/Phospholipidshttp://www.biology-online.org/dictionary/Fatty_acidshttp://www.biology-online.org/dictionary/Glycolipidshttp://www.biology-online.org/dictionary/Cholesterolhttp://www.biology-online.org/dictionary/Phospholipidshttp://www.biology-online.org/dictionary/Hydrophilichttp://www.biology-online.org/dictionary/Hydrophobichttp://www.biology-online.org/dictionary/Nonpolarhttp://www.biology-online.org/dictionary/Polar

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targeted incorporation of synthetic amino acidswhich can mimic natural amphiphilic amino

acids possessing multiple affinities to different chemical motifs.

Ref :http://pubs.rsc.org/en/content/articlelanding/2013/sc/c2sc21639f#!divAbstract

http://www.biology-online.org/dictionary/Amphipathic

http://pubs.rsc.org/en/content/articlelanding/2013/sc/c2sc21639f#!divAbstracthttp://pubs.rsc.org/en/content/articlelanding/2013/sc/c2sc21639f#!divAbstracthttp://pubs.rsc.org/en/content/articlelanding/2013/sc/c2sc21639f#!divAbstracthttp://pubs.rsc.org/en/content/articlelanding/2013/sc/c2sc21639f#!divAbstract