BIOCHEMISTRY FOURTH EDITION ACTUAL
PAPER 2026 VERIFIED ANSWER KEY STUDY
GUIDE REVISION PACK
◉ Which statement regarding protein secondary structures is
correct?
a. β-strands allow α-helices to interact with one another.
b. Protein α-helices alternate with β-strands in stabilizing protein
structure.
c. Protein α-helices are left handed, whereas β-sheets are right
handed in arrangement.
d. Protein α-helices and β-strands differ in that α-helices are
stabilized by intrahelical
hydrogen bonds, whereas β-strands are stabilized by hydrogen
bonds across adjacent strands.
Answer: D
◉ Which of the following statements about α-helices and β-sheets
are FALSE?
a. They are both incompatible with the amino acid proline.
b. They both interact with other protein elements through amino
acid side chains that stick out.
, c. They both contain a recurring pattern of hydrogen bonds from one
peptide bond to another peptide bond.
d. They both give rise to similar tertiary structures.
Answer: D
◉ An α-helix has the sequence: NH3+-Ser-Glu-Gly-Asp-Trp-Gln-Leu-
His-Val-Phe-Ala-Lys-Val-Glu-COO-. The carbonyl oxygen (in the
peptide bond) of the histidine residue is hydrogen bonded to the
amide nitrogen of
a. Asp.
b. Lys.
c. Trp.
d. Ala.
Answer: B
◉ Which of the following statements is true about α-helices?
a. The center of the helix is an open channel.
b. There are about seven amino acids per helical turn.
c. The amide backbone dipoles line up in one direction.
d. The helical backbone structure is stabilized by ionic interactions.
Answer: C
◉ Which statement about the α-helix is true?
PAPER 2026 VERIFIED ANSWER KEY STUDY
GUIDE REVISION PACK
◉ Which statement regarding protein secondary structures is
correct?
a. β-strands allow α-helices to interact with one another.
b. Protein α-helices alternate with β-strands in stabilizing protein
structure.
c. Protein α-helices are left handed, whereas β-sheets are right
handed in arrangement.
d. Protein α-helices and β-strands differ in that α-helices are
stabilized by intrahelical
hydrogen bonds, whereas β-strands are stabilized by hydrogen
bonds across adjacent strands.
Answer: D
◉ Which of the following statements about α-helices and β-sheets
are FALSE?
a. They are both incompatible with the amino acid proline.
b. They both interact with other protein elements through amino
acid side chains that stick out.
, c. They both contain a recurring pattern of hydrogen bonds from one
peptide bond to another peptide bond.
d. They both give rise to similar tertiary structures.
Answer: D
◉ An α-helix has the sequence: NH3+-Ser-Glu-Gly-Asp-Trp-Gln-Leu-
His-Val-Phe-Ala-Lys-Val-Glu-COO-. The carbonyl oxygen (in the
peptide bond) of the histidine residue is hydrogen bonded to the
amide nitrogen of
a. Asp.
b. Lys.
c. Trp.
d. Ala.
Answer: B
◉ Which of the following statements is true about α-helices?
a. The center of the helix is an open channel.
b. There are about seven amino acids per helical turn.
c. The amide backbone dipoles line up in one direction.
d. The helical backbone structure is stabilized by ionic interactions.
Answer: C
◉ Which statement about the α-helix is true?
