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CHEM 210 Biochemistry Module 4
Exam (2025/2026) – Portage Learning
Questions and Verified Answers |
100% Guarantee Pass
1. Which amino acid has a sulfhydryl group in its side chain?
a) Methionine
b) Cysteine
c) Serine
d) Threonine
Rationale: Cysteine contains a sulfhydryl (-SH) group, which can form disulfide bonds,
per Portage Learning’s focus on amino acid side chain properties.
2. What type of bond links amino acids in a polypeptide chain?
a) Hydrogen bond
b) Peptide bond
c) Disulfide bond
d) Ionic bond
Rationale: A peptide bond is a covalent amide bond formed between the carboxyl group
of one amino acid and the amino group of another, per Portage Learning’s protein
structure content.
3. Which level of protein structure is determined by the sequence of amino acids?
a) Secondary
b) Primary
c) Tertiary
d) Quaternary
Rationale: The primary structure is the linear sequence of amino acids, per Portage
Learning’s protein structure hierarchy.
4. What is the primary force stabilizing the secondary structure of proteins?
a) Disulfide bonds
b) Hydrogen bonds
c) Hydrophobic interactions
d) Ionic bonds
Rationale: Hydrogen bonds between backbone atoms stabilize alpha helices and beta
sheets, per Portage Learning’s secondary structure focus.
5. Which amino acid is most likely to disrupt an alpha helix?
a) Valine
b) Proline
c) Leucine
, 2
d) Alanine
Rationale: Proline’s rigid ring structure causes a kink, disrupting alpha helices, per
Portage Learning’s structural biochemistry.
6. What is the role of an enzyme’s active site?
a) Stabilize protein folding
b) Bind substrate and catalyze reaction
c) Form peptide bonds
d) Store energy
Rationale: The active site binds substrates and facilitates catalysis, per Portage
Learning’s enzyme function principles.
7. Which amino acid has a positively charged side chain at pH 7?
a) Glutamate
b) Lysine
c) Aspartate
d) Cysteine
Rationale: Lysine’s side chain (amino group) is positively charged at physiological pH,
per Portage Learning’s amino acid properties.
8. What type of interaction stabilizes the tertiary structure of a protein?
a) All of the above
b) Hydrogen bonds
c) Disulfide bonds
d) Hydrophobic interactions
Rationale: Tertiary structure is stabilized by hydrogen bonds, disulfide bonds,
hydrophobic interactions, and ionic bonds, per Portage Learning’s protein folding
content.
9. Which enzyme class catalyzes the transfer of functional groups?
a) Hydrolases
b) Transferases
c) Lyases
d) Oxidoreductases
Rationale: Transferases catalyze group transfers (e.g., phosphate), per Portage
Learning’s enzyme classification.
10. What is the primary function of a chaperone protein?
a) Catalyze reactions
b) Assist in protein folding
c) Transport amino acids
d) Form peptide bonds
Rationale: Chaperones help proteins fold correctly, preventing misfolding, per Portage
Learning’s protein structure content.
11. Which amino acid is nonpolar and aliphatic?
a) Histidine
b) Leucine
c) Arginine
d) Aspartic acid
Rationale: Leucine has a nonpolar, aliphatic side chain (isobutyl group), per Portage
Learning’s amino acid classification.
CHEM 210 Biochemistry Module 4
Exam (2025/2026) – Portage Learning
Questions and Verified Answers |
100% Guarantee Pass
1. Which amino acid has a sulfhydryl group in its side chain?
a) Methionine
b) Cysteine
c) Serine
d) Threonine
Rationale: Cysteine contains a sulfhydryl (-SH) group, which can form disulfide bonds,
per Portage Learning’s focus on amino acid side chain properties.
2. What type of bond links amino acids in a polypeptide chain?
a) Hydrogen bond
b) Peptide bond
c) Disulfide bond
d) Ionic bond
Rationale: A peptide bond is a covalent amide bond formed between the carboxyl group
of one amino acid and the amino group of another, per Portage Learning’s protein
structure content.
3. Which level of protein structure is determined by the sequence of amino acids?
a) Secondary
b) Primary
c) Tertiary
d) Quaternary
Rationale: The primary structure is the linear sequence of amino acids, per Portage
Learning’s protein structure hierarchy.
4. What is the primary force stabilizing the secondary structure of proteins?
a) Disulfide bonds
b) Hydrogen bonds
c) Hydrophobic interactions
d) Ionic bonds
Rationale: Hydrogen bonds between backbone atoms stabilize alpha helices and beta
sheets, per Portage Learning’s secondary structure focus.
5. Which amino acid is most likely to disrupt an alpha helix?
a) Valine
b) Proline
c) Leucine
, 2
d) Alanine
Rationale: Proline’s rigid ring structure causes a kink, disrupting alpha helices, per
Portage Learning’s structural biochemistry.
6. What is the role of an enzyme’s active site?
a) Stabilize protein folding
b) Bind substrate and catalyze reaction
c) Form peptide bonds
d) Store energy
Rationale: The active site binds substrates and facilitates catalysis, per Portage
Learning’s enzyme function principles.
7. Which amino acid has a positively charged side chain at pH 7?
a) Glutamate
b) Lysine
c) Aspartate
d) Cysteine
Rationale: Lysine’s side chain (amino group) is positively charged at physiological pH,
per Portage Learning’s amino acid properties.
8. What type of interaction stabilizes the tertiary structure of a protein?
a) All of the above
b) Hydrogen bonds
c) Disulfide bonds
d) Hydrophobic interactions
Rationale: Tertiary structure is stabilized by hydrogen bonds, disulfide bonds,
hydrophobic interactions, and ionic bonds, per Portage Learning’s protein folding
content.
9. Which enzyme class catalyzes the transfer of functional groups?
a) Hydrolases
b) Transferases
c) Lyases
d) Oxidoreductases
Rationale: Transferases catalyze group transfers (e.g., phosphate), per Portage
Learning’s enzyme classification.
10. What is the primary function of a chaperone protein?
a) Catalyze reactions
b) Assist in protein folding
c) Transport amino acids
d) Form peptide bonds
Rationale: Chaperones help proteins fold correctly, preventing misfolding, per Portage
Learning’s protein structure content.
11. Which amino acid is nonpolar and aliphatic?
a) Histidine
b) Leucine
c) Arginine
d) Aspartic acid
Rationale: Leucine has a nonpolar, aliphatic side chain (isobutyl group), per Portage
Learning’s amino acid classification.
