1. The torsion angles which describe the protein backbone are: Alpha, beta, gamma Phi, psi, omega Phi, psi, omega, chi
2. The phi angle is defined by the atoms C-N-CA-C CA-C-N-CA N-CA-C-N
3. The psi angle is defined by the atoms C-N-CA-C CA-C-N-CA N-CA-C-N
4. The omega angle is defined by the atoms C-N-CA-C CA-C-N-CA N-CA-C-N
5. The peptide bond is: A single bond A double bond A partial double bond
6. The nature of the peptide bond results from: Delocalization of a lone pair of electrons on the carbonyl oxygen resulting in a partial positive charge on the oxygen and a partial negative charge on the backbone nitrogen Delocalization of a lone pair of electrons on the backbone nitrogen resulting in a partial positive charge on the nitrogen and a partial negative charge on the carbonyl oxygen
7. The peptide bond is always: Close to +/- 90 degrees Close to 90 degrees Close to 180 degrees Close to 0 degrees Freely rotatable None of the above
8. Which direction corresponds to a positive torsion angle? Moving the near atom anti-clockwise or the distant atom clockwise Moving the near atom clockwise or the distant atom anti-clockwise
9. The peptide bond is often close to 0 degrees when the following amino acid is: Glycine Proline Alanine Tryptophan