Exam 1: Discussion Clickers Flashcards
Which of the following statements is true about the βαβ motif?
A) βαβ motif is composed of two antiparallel beta strands and one alpha
helix.
B) Proteins with beta structure are built from multiple βαβ motifs.
C) βαβ motif is built from two parallel beta strands connected with an alpha
helix.
D) βαβ motif was first identified from the structure of green fluorescence
protein.
C) βαβ motif is built from two parallel beta strands connected with an alpha
helix.
Which of the following peptides contains heptad repeats and can potentially form coiled-coil structure with each other in an aqueous environment?
A.MKQLEDKVEELLSKVYHLENE
B.VKQSEKDSEEVSLKNYQSEDN
C.LSFAAAMNGLALSFAAMNDEN
D.None of these peptides contains heptad repeats.
A.MKQLEDKVEELLSKVYHLENE
Which of the following secondary structures is most likely to be found in a membrane-embedded portion of a protein?
A.An alpha helix composed entirely of hydrophobic residues
B.A single extended beta strand
C.An open antiparallel beta sheet composed of hydrophobic
residues
D.An open parallel beta sheet composed of hydrophilic
residues
A. An alpha helix composed entirely of hydrophobic residues
Which of the following statements about hydrophobic interaction is correct?
A. Hydrophobic interaction is very
important for membrane
formation.
B. During protein folding, polar side
chains of amino acids are buried
inside via hydrophobic interaction.
C. Hydrophobic effect occurs
because the hydrophobic
molecules attract each other.
D. Hydrophobic interaction is a type
of electrostatic interaction.
A. Hydrophobic interaction is very
important for membrane
formation.
What is the conjugate acid of PO4^3–?
A. HPO4^2–
B. H2PO4^–
C. H3PO4
A. HPO4^2–
Under what conditions would a carboxyl group be mostly charged?
A. pH < pK
B. pH = pK
C. pH > pK
C. pH > pK
Ceviche is a dish in which raw fish is marinated with lime juice. Lime juice contains citric acid which has a pKa of 6.41. What would be the ratio of citrate: citric acid if the pH of the dish is 5.5?
A.–0.91
B.0.12
C.0.40
D.1.57
E.3.14
B.0.12
Which of the 20 common amino acids does NOT exhibit chirality?
A. Glycine
B. Alanine
C. Serine
D. Leucine
E. None – they all do
A. Glycine
Which amino acid would most likely be found in the internal core of a globular protein?
A. Lys
B. Trp
C. Glu
D. Ser
B. Trp
The electrostatic properties of a polypeptide depend primarily on
A. the number of amino acid residues.
B. the number of peptide bonds.
C. the identity of the terminal amino acids.
D. the identities of the side chains in the polypeptide chain.
D. the identities of the side chains in the polypeptide chain.
