BIOC 384 Exam 1 Exam Prep 2026/2027 | Questions
& Correct Answers | Graded A+
1. What sequence of atoms represents the covalent backbone of a dipeptide
from the N to C terminus?
CNCCNC
NCCNCC
NCONCO
NCCONCCO
2. What would be the approximate charge on the following peptide at a pH of
7? ELVIS
+1
-2
-1
0
+2
3. Which amino acids are typically hydrophobic and likely to be found in the
interior of water-soluble proteins?
Leu, Ile, Val, Ala
Asp, Cys, Lys, Glu
Cys, Thr, Ser, Glu
Glu, Thr, Phe, Arg
4. What are amphipathic α-helices often part of?
, D. A and B
C. A single transmembrane α helix
A. A coiled-coil domain
B. An ion channel
E. B and C
5. Discuss why the energy charge value may not accurately reflect the energy
status of a healthy cell.
The energy charge value is influenced solely by environmental
factors.
The energy charge value is always equal to 1 in healthy cells.
The energy charge value only considers ATP levels.
The energy charge value does not account for other energy-
carrying molecules and cellular conditions.
6. The points in the Ramachandran plot are derived by *see 30*
placing each amino acid in regions commonly occupied by that amino
acid.
counting the number of amino acids and placing points in allowed
regions.
experimentally measuring the optical rotation of polarized light
measuring the φ and ψ angles in an experimentally determined
protein crystal structure.
7. Describe how the amino acid sequence influences the stability of β sheets in
proteins.
, The amino acid sequence dictates the overall shape of the protein, not
the stability of β sheets.
The amino acid sequence determines the specific interactions and
hydrogen bonding patterns that stabilize β sheets.
The amino acid sequence has no effect on the stability of β sheets.
The amino acid sequence only affects the primary structure, not the
secondary structure.
8. Which amino acid is classified as an aromatic amino acid?
Serine
Phenylalanine
Aspartate
Isoleucine
9. Describe the significance of the isoelectric point in the behavior of amino
acids in solution.
The isoelectric point indicates the temperature at which amino acids
denature.
The isoelectric point is significant because it is the pH at which an
amino acid has no net charge, affecting its solubility and interaction
with other molecules.
The isoelectric point determines the molecular weight of the amino
acid.
The isoelectric point is the pH at which amino acids are fully
protonated.
, 10. If the pentapeptide AHDLV is placed in a solution with a pH of 5, what would
you predict its charge to be, and why?
-1
0
+1
-2
11. What is the definition of the isoelectric point (pI) in relation to zwitterions?
When the molecule has a single electric charge.
At pH = 7.0.
At the pH when all negative charges on a zwitterion counter the
positive charges.
When all of the acidic protons are neutralized with base.
12. What was the principal conclusion drawn from the Anfinsen experiments on
the denaturation and renaturation of ribonuclease A?
primary structure drives the correct folding of the native protein
conformation
proteins must possess disulfide bonds in order to fold properly
protein folding is guided by the formation of disulfide bonds
hydrogen bonds are responsible for protein folding
reduction of disulfide bonds with mercaptoethanol does not cause
denaturation
13. If a mutation occurs that prevents the transcription of messenger RNA from
DNA, what would be the most immediate effect on protein synthesis?
& Correct Answers | Graded A+
1. What sequence of atoms represents the covalent backbone of a dipeptide
from the N to C terminus?
CNCCNC
NCCNCC
NCONCO
NCCONCCO
2. What would be the approximate charge on the following peptide at a pH of
7? ELVIS
+1
-2
-1
0
+2
3. Which amino acids are typically hydrophobic and likely to be found in the
interior of water-soluble proteins?
Leu, Ile, Val, Ala
Asp, Cys, Lys, Glu
Cys, Thr, Ser, Glu
Glu, Thr, Phe, Arg
4. What are amphipathic α-helices often part of?
, D. A and B
C. A single transmembrane α helix
A. A coiled-coil domain
B. An ion channel
E. B and C
5. Discuss why the energy charge value may not accurately reflect the energy
status of a healthy cell.
The energy charge value is influenced solely by environmental
factors.
The energy charge value is always equal to 1 in healthy cells.
The energy charge value only considers ATP levels.
The energy charge value does not account for other energy-
carrying molecules and cellular conditions.
6. The points in the Ramachandran plot are derived by *see 30*
placing each amino acid in regions commonly occupied by that amino
acid.
counting the number of amino acids and placing points in allowed
regions.
experimentally measuring the optical rotation of polarized light
measuring the φ and ψ angles in an experimentally determined
protein crystal structure.
7. Describe how the amino acid sequence influences the stability of β sheets in
proteins.
, The amino acid sequence dictates the overall shape of the protein, not
the stability of β sheets.
The amino acid sequence determines the specific interactions and
hydrogen bonding patterns that stabilize β sheets.
The amino acid sequence has no effect on the stability of β sheets.
The amino acid sequence only affects the primary structure, not the
secondary structure.
8. Which amino acid is classified as an aromatic amino acid?
Serine
Phenylalanine
Aspartate
Isoleucine
9. Describe the significance of the isoelectric point in the behavior of amino
acids in solution.
The isoelectric point indicates the temperature at which amino acids
denature.
The isoelectric point is significant because it is the pH at which an
amino acid has no net charge, affecting its solubility and interaction
with other molecules.
The isoelectric point determines the molecular weight of the amino
acid.
The isoelectric point is the pH at which amino acids are fully
protonated.
, 10. If the pentapeptide AHDLV is placed in a solution with a pH of 5, what would
you predict its charge to be, and why?
-1
0
+1
-2
11. What is the definition of the isoelectric point (pI) in relation to zwitterions?
When the molecule has a single electric charge.
At pH = 7.0.
At the pH when all negative charges on a zwitterion counter the
positive charges.
When all of the acidic protons are neutralized with base.
12. What was the principal conclusion drawn from the Anfinsen experiments on
the denaturation and renaturation of ribonuclease A?
primary structure drives the correct folding of the native protein
conformation
proteins must possess disulfide bonds in order to fold properly
protein folding is guided by the formation of disulfide bonds
hydrogen bonds are responsible for protein folding
reduction of disulfide bonds with mercaptoethanol does not cause
denaturation
13. If a mutation occurs that prevents the transcription of messenger RNA from
DNA, what would be the most immediate effect on protein synthesis?
