#Question id: 732
#Unit 1. Molecules and their Interaction Relevant to Biology
Ramachandran plots can help increase the accuracy of models derived from x-ray crystallography data. The plot below was created by measuring phi, and psi for each amino acid residue in a 2.2 A resolution crystal structure. In the plot, which excludes Gly and Pro residues, selected residues (dots) are numbered 1 through 5.
Which of the following statements can be correctly stated for this plot in reference to selected residues?
A. Residues 1 and 3 are in either B sheets
B. residue 2 is in a right-handed a helix, and residue 4 is in a left-handed a helix.
C. If residue 5 were Gly, it might be in an acceptable position in the plot
#Question id: 733
#Unit 1. Molecules and their Interaction Relevant to Biology
Which one of the statements on protein conformation, detailed below is INCORRECT?
#Question id: 734
#Unit 1. Molecules and their Interaction Relevant to Biology
Which of the following statements is true for two different tripeptides consisting of either glycine or proline?
#Question id: 735
#Unit 1. Molecules and their Interaction Relevant to Biology
The a-keratin chains indicated by the diagram below have undergone one chemical step. To alter the shape of the a-keratin chains—as in hair waving—what subsequent steps are required?
#Question id: 736
#Unit 1. Molecules and their Interaction Relevant to Biology
The most important contribution to the stability of a protein’s conformation appears to be the:
#Question id: 737
#Unit 1. Molecules and their Interaction Relevant to Biology
Which structure below indicates the proper hydrogen-bonding pattern between amino acids in an α-helix? (Dashed lines represent the hydrogen bonds.)