One of the most common features of anion binding sites is the presence of an a-helical structure. Using a schematic diagram of a helix, describe what you've observed. The direction of the dipole and the N-terminus of the helix should be clearly indicated. Show the (general) base structure of the glutamic acid functional group side chain.

Proline is known as a beta sheet and alpha helix "breaker ," therefore proline is rarely found in beta sheets or alpha helices. why do you think this is? In your explanation, you should describe the specific molecular interactions necessary for the formation of alpha-helices and beta-sheets. Please be as specific as possible.

α-Keratin is an intermediate filament with a basic structural unit of two a helices in a coiled coil. Each helix has a seven-residue repeating unit (heptad repeat). A representation of the a helices of a coiled coil dimer is shown. Each letter represents a different amino acid residue. f g d e Review the table of amino acids. a d g f Identify the three true statements about the structure of keratin. ☐ The a helix of the coiled coil is wound less tightly than predicted for an α helix. ☐ Each polypeptide in the dimer has 3.6 residues per turn, and a nonpolar group occurs every 3.5 residues, resulting in a slight winding, or twist, around the other polypeptide, forming a coiled coil. Arg-Ala-His-Glu-His-Thr-Asp is a likely repeat in the a helix of keratin. ☐ Val-Thr-Asp-Ala-Glu-Arg-His is a likely repeat in the a helix of keratin. ☐ The residues at positions b and c are less likely to be polar or charged because they are in contact with the solvent. ☐ Keratin molecules are very strong due…

What does this statement mean: "Upon folding of a protein many main chain amides replace their hydrogen bonds to water for those with other amide bonds"  Is this true for alpha helix in proline racemase? and is there a pattern?