What is the hydrogen bonding pattern within an alpha helix?   a. Lone pair on C=O of residue i to hydrogen on N-H of residue i+3.   b. Lone pair on C=O of residue i to hydrogen on N-H of residue i+4.   c. Hydrogen of N-H of residue i to hydrogen on N-H of residue i+3.   d. Lone pair on C=O of residue i to hydrogen on N-H of residue i+2.

In the alpha-helices, which of the following statement is NOT true?   a.   Backbone carbonyl oxygen of residue (i) hydrogen bonds to backbone NH of the fourth residue of chain of residue (i + 4).   b.   Side chains project out from an α-helix.   c.   Hydrogen bonds are almost straight and parallel to the helix axis.   d.   Helix has a macrodipole.   e.   The rise or advance per amino acid residue is 0.54 nm.

Because of the helix dipole, the phosphate ions are likely to bind to a.   The side-chains of a-helix   b.   The C-terminus of a-helix   c.   The N-terminus of a-helix   d.   The carbonyl group of the peptide bond

what does it mean to say that trends in a double helix is antiparallel? A. They each have a sugar-phoshate backbone. B. They each have a 5'-3'  directionality (or polarity). C. They have opposite directionalty in terms of relative positions of 5' and 3' ends.

What is one reason that protein folding intermediates are prone to aggregation?   a. Their hydrophobic chemical groups are exposed to solvent   b. They have not formed enough hydrogen bonds   c. They are not globular enough   d.  They have not formed any disulfide bonds

Which of the following descriptions best describes the composition of nucleotides?   Group of answer choices A. a pentose sugar and a purine or pyrimidine B. a nitrogenous base, a phosphate group, and a pentose sugar C. a nitrogenous base and a pentose sugar D. a nitrogenous base and a phosphate group E. a phosphate group and an adenine or uracil

Draw the structure of STVWY at pH 13. Connect with an arrow the C=0 of the N- terminal residue to the NH that it would be hydrogen bonded to if the peptide was forming a a-helix?

RNA was isolated from a tissue with a solution buffered at pH 12.  However, no RNA was obtained. Why? a.   The 5’ OH group of the ribose is protonated (positive charged) at pH 12 and reacts with the phosphorus atom to cleave the phosphodiester bond.   b.   The 5’ OH group of the ribose is deprotonated (negative charged) at pH 12 and reacts with the phosphorus atom to cleave the phosphodiester bond.   c.   The 2’ OH group of the ribose is deprotonated (negative charged) at pH 12 and reacts with the phosphorus atom to cleave the phosphodiester bond.   d.   The 2’ OH group of the ribose is protonated (positive charged) at pH 12 and reacts with the phosphorus atom to cleave the phosphodiester bond.

Describe the helix-turn-helix (HTF) motif?

Double stranded nucleic acids are stabilized by all of the following except: A. Hydrophobic stacking between bases B. Hydrogen bonding between pyrimidines and purines C. Repulsion of phosphate groups D. Phosphodiester backbones E. Hydrogen bonding via ether linkages