Midterm 1 multiple choice

Midterm 1 multiple choice - pleated sheet are characterized...

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β pleated sheet are characterized by: a. disulfide bridges between cysteine amino acids. b. parallel regions of the polypeptide chain held together by hydrophobic interactions. c. folds stablized by hydrogen bonds betwwen segments of the polypeptide backbone. d. membrane sheets composed of phospholipids. e. hydrogen bonds between adjacent cellulose molecules. The correct answer is C. Because β pleated sheet is composed of 2 or more than polypeptide chains called β strands. β pleated sheet are stabblized by hyndrogen bonding between polypeptide strains. The other answers are not correct due to the interaction or other aspects. Which Amino Acid form(s) would be found at the highest concentration when in water solution? (a) The fully protonated form (b) The Zwitterion (c) The fully deprotonated form (d) A and C (e) All of the above The answer is (b) The Zwitterion. The partially protonated zwitterion has a net charge of 0, so it tends to favor neutral solutions like water (pH 6-7). The fully protonated form of the amino acid would be found in acidic solutions with a lower pH, due to the higher concentration of [H+] ions in those solutions favoring protonation of the amino group. The fully deprotonated form of the amino acid would be found in basic solutions with a higher pH, due to the lower concentration of [H+] favoring deprotonation of the carboxyl group. In the book "Through the Looking Glass and What Alice Found There" by Lewis Carroll, Alice (from Alice-in-Wonderland) walks through a mirror into a mirror-image world. If Alice remained unchanged, which substance(s) would she be able to metabolize: a.) ethanol b.) glycine c.) water e.) all of the above E is the correct answer. All chiral amino acids in the mirror image world would be d-form, and Alice would not be able to metabolize them (her enzymes would only be able to metabolize l- form amino acids), resulting in a horribly horrible death by starvation. All the molecules listed are achiral, so she'd be able to drink liquor and hydrate while metabolizing the only achiral amino acid she could. The bonding of two amino acid molecules to form a larger molecule requires a. the release of a water molecule b. the release of a carbon dioxide molecule c. the addition of a nitrogen atom d. the addition of a water molecule e. an increase in activation energy Answer is A, a water molecule will be released in order to form a peptide bond between the carboxy terminal and the amine group
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The Ramachandran Plot represents: a) peptide-bond resonance structures b) polyampholytic behavior of a polypeptide c) areas of steric exclusion in the polypeptide chain d) the ionization state as a function of pH e) none of the above The answer is (c): Areas of steric exclusion in the polypeptide chain The Ramachandran Diagram. .. a) shows how the trans form of the peptide bond is more favorable than the cis.
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Midterm 1 multiple choice - pleated sheet are characterized...

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