BIOCHEM CHAPTER 4 EXAM 5
All of the following are considered "weak" interactions in proteins, except: - CORRECT
ANSWER-peptide bonds.
The most important contribution to the stability of a protein's conformation appears to be
the: - CORRECT ANSWER-entropy increase from the decrease in ordered water
molecules forming a solvent shell around it.
In an aqueous solution, protein conformation is determined by two major factors. One is
the formation of the maximum number of hydrogen bonds. The other is the: -
CORRECT ANSWER-placement of hydrophobic amino acid residues within the interior
of the protein.
Pauling and Corey's studies of the peptide bond showed that: - CORRECT ANSWER-
peptide bonds are essentially planar, with no rotation about the C—N axis.
In the diagram below, the plane drawn behind the peptide bond indicates the: -
CORRECT ANSWER-absence of rotation around the C—N bond because of its partial
double-bond character.
Which of the following best represents the backbone arrangement of two peptide
bonds? - CORRECT ANSWER-Ca—C—N—Ca—C—N
Which of the following pairs of bonds within a peptide backbone show free rotation
around both bonds? - CORRECT ANSWER-C—C and N—C
Roughly how many amino acids are there in one turn of an helix? - CORRECT
ANSWER-3.6
In the helix the hydrogen bonds: - CORRECT ANSWER-are roughly parallel to the axis
of the helix.
In an a-helix, the R groups on the amino acid residues: - CORRECT ANSWER-are
found on the outside of the helix spiral.
Thr and/or Leu residues tend to disrupt an a-helix when they occur next to each other in
a protein because: - CORRECT ANSWER-steric hindrance occurs between the bulky
Thr side chains.
A d-amino acid would interrupt an helix made of l-amino acids. Another naturally
occurring hindrance to the formation of an helix is the presence of: - CORRECT
ANSWER-a Pro residue.
All of the following are considered "weak" interactions in proteins, except: - CORRECT
ANSWER-peptide bonds.
The most important contribution to the stability of a protein's conformation appears to be
the: - CORRECT ANSWER-entropy increase from the decrease in ordered water
molecules forming a solvent shell around it.
In an aqueous solution, protein conformation is determined by two major factors. One is
the formation of the maximum number of hydrogen bonds. The other is the: -
CORRECT ANSWER-placement of hydrophobic amino acid residues within the interior
of the protein.
Pauling and Corey's studies of the peptide bond showed that: - CORRECT ANSWER-
peptide bonds are essentially planar, with no rotation about the C—N axis.
In the diagram below, the plane drawn behind the peptide bond indicates the: -
CORRECT ANSWER-absence of rotation around the C—N bond because of its partial
double-bond character.
Which of the following best represents the backbone arrangement of two peptide
bonds? - CORRECT ANSWER-Ca—C—N—Ca—C—N
Which of the following pairs of bonds within a peptide backbone show free rotation
around both bonds? - CORRECT ANSWER-C—C and N—C
Roughly how many amino acids are there in one turn of an helix? - CORRECT
ANSWER-3.6
In the helix the hydrogen bonds: - CORRECT ANSWER-are roughly parallel to the axis
of the helix.
In an a-helix, the R groups on the amino acid residues: - CORRECT ANSWER-are
found on the outside of the helix spiral.
Thr and/or Leu residues tend to disrupt an a-helix when they occur next to each other in
a protein because: - CORRECT ANSWER-steric hindrance occurs between the bulky
Thr side chains.
A d-amino acid would interrupt an helix made of l-amino acids. Another naturally
occurring hindrance to the formation of an helix is the presence of: - CORRECT
ANSWER-a Pro residue.
