Search results
Results from the WOW.Com Content Network
Depicted above is the monomeric ELP unit. X represents an arbitrary amino acid. Polymers are formed from this pentapeptide monomeric unite. Elastin-like polypeptides (ELPs) are synthetic biopolymers with potential applications in the fields of cancer therapy, tissue scaffolding, metal recovery, and protein purification.
Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is significantly less volatile than simpler phenolic antioxidants such as butylhydroxytoluene (BHT). This makes it more suitable to stabilising plastics, as it is not driven out by the high temperatures experienced during plastic extrusion and moulding, [2] when they are heated to 150-320 °C (300–600 °F). [3]
Alginate: Alginate is the most copious marine natural polymer derived from brown seaweed. Alginate biopolymer applications range from packaging, textile and food industry to biomedical and chemical engineering. The first ever application of alginate was in the form of wound dressing, where its gel-like and absorbent properties were discovered.
The 3 10 helix was eventually confirmed by Kendrew in his 1958 structure of myoglobin, [8] and was also found in Perutz' 1960 determination of the structure of haemoglobin [9] [10] [11] and in subsequent work on both its deoxygenated [12] [13] and oxygenated forms. [14] [15] The 3 10 helix is now known to be the third principal structure to ...
The resulting polyamides are known as proteins or polypeptides. In the diagram below, consider the amino-acids as single aliphatic monomers reacting with identical molecules to form a polyamide, focusing on solely the amine and acid groups. Ignore the substituent R groups – under the assumption the difference between the R groups are negligible:
Both the α-helix and the β-sheet represent a way of saturating all the hydrogen bond donors and acceptors in the peptide backbone. Some parts of the protein are ordered but do not form any regular structures. They should not be confused with random coil, an unfolded polypeptide chain lacking any fixed three-dimensional structure.
In polymer science, the Lifson–Roig model [1] is a helix-coil transition model applied to the alpha helix-random coil transition of polypeptides; [2] it is a refinement of the Zimm–Bragg model that recognizes that a polypeptide alpha helix is only stabilized by a hydrogen bond only once three consecutive residues have adopted the helical conformation.
α-helices are shown as coiled ribbons or thick tubes, β-sheets as arrows, and non-repetitive coils or loops as lines or thin tubes. The direction of the polypeptide chain is shown locally by the arrows, and may be indicated overall by a colour ramp along the length of the ribbon.