CHEM 210 Biochemistry Final Exam (Portage
Learning) 2026 | Actual Questions & Verified
Answers | Complete Study Guide for A+ Pass
First Attempt
• This study guide contains 200 verified MCQs for CHEM 210 Biochemistry (Portage
Learning) — each question includes 5 options, a highlighted correct answer, and a
EXPERT RATIONALE to reinforce understanding.
• Read each question carefully, attempt your answer before checking, and use the
EXPERT RATIONALE section to deeply understand the concept — not just
memorize the answer.
CHEM 210 BIOCHEMISTRY FINAL EXAM Portage Learning | 2026 | Complete
Study Guide
QUESTION 1
Which of the following best describes the primary structure of a protein?
A) The three-dimensional folding of the polypeptide chain
B) The coiling of the polypeptide into an alpha helix
C) The arrangement of multiple polypeptide subunits
D) The interactions between R groups of amino acids
E) The linear sequence of amino acids joined by peptide bonds
✔ Correct Answer: E
EXPERT RATIONALE: The primary structure of a protein refers specifically to the
sequence of amino acids linked together by peptide bonds. This sequence is
determined by the gene and serves as the foundation for all higher levels of protein
structure.
QUESTION 2
,Which bond is responsible for linking amino acids together in a polypeptide
chain?
A) Hydrogen bond
B) Ionic bond
C) Disulfide bond
D) Van der Waals interaction
E) Peptide bond
✔ Correct Answer: E
EXPERT RATIONALE: Peptide bonds are covalent bonds formed between the
carboxyl group of one amino acid and the amino group of the next, releasing water
in a condensation reaction. They form the backbone of all polypeptide chains.
QUESTION 3
What is the term for the process by which a protein loses its three-
dimensional structure?
A) Phosphorylation
B) Translation
C) Glycosylation
D) Hydrolysis
E) Denaturation
✔ Correct Answer: E
EXPERT RATIONALE: Denaturation refers to the unfolding or disruption of a
protein's native three-dimensional structure due to heat, pH changes, chemicals, or
other factors. It typically results in loss of function without breaking peptide bonds.
QUESTION 4
,Which of the following amino acids contains a sulfur atom in its side chain?
A) Alanine
B) Glycine
C) Lysine
D) Phenylalanine
E) Cysteine
✔ Correct Answer: E
EXPERT RATIONALE: Cysteine contains a thiol (-SH) group in its side chain. This
sulfur-containing group is important for forming disulfide bonds that stabilize
protein structure, especially in extracellular proteins.
QUESTION 5
Alpha helices and beta sheets are examples of which level of protein
structure?
A) Primary structure
B) Quaternary structure
C) Tertiary structure
D) Domain structure
E) Secondary structure
✔ Correct Answer: E
EXPERT RATIONALE: Secondary structure refers to the local folding patterns of
the polypeptide backbone stabilized by hydrogen bonds. The alpha helix and beta-
pleated sheet are the two most common forms of secondary structure.
QUESTION 6
, Which of the following is a characteristic of enzyme active sites?
A) They are located far from the substrate binding region
B) They are made up entirely of hydrophobic residues
C) They change irreversibly after every reaction
D) They bind only to cofactors
E) They are specific in shape and chemical nature to their substrates
✔ Correct Answer: E
EXPERT RATIONALE: The active site of an enzyme is a specific region that binds
the substrate through complementary shape, charge, and chemical interactions.
This specificity is key to the enzyme's ability to catalyze particular reactions.
QUESTION 7
What does Km represent in enzyme kinetics?
A) Maximum reaction velocity
B) Total enzyme concentration
C) Product inhibition constant
D) Activation energy of the reaction
E) The substrate concentration at which reaction velocity is half of Vmax
✔ Correct Answer: E
EXPERT RATIONALE: Km (Michaelis constant) is the substrate concentration at
which the reaction velocity is half the maximum (Vmax). A low Km indicates high
affinity between enzyme and substrate, while a high Km indicates low affinity.
QUESTION 8
Learning) 2026 | Actual Questions & Verified
Answers | Complete Study Guide for A+ Pass
First Attempt
• This study guide contains 200 verified MCQs for CHEM 210 Biochemistry (Portage
Learning) — each question includes 5 options, a highlighted correct answer, and a
EXPERT RATIONALE to reinforce understanding.
• Read each question carefully, attempt your answer before checking, and use the
EXPERT RATIONALE section to deeply understand the concept — not just
memorize the answer.
CHEM 210 BIOCHEMISTRY FINAL EXAM Portage Learning | 2026 | Complete
Study Guide
QUESTION 1
Which of the following best describes the primary structure of a protein?
A) The three-dimensional folding of the polypeptide chain
B) The coiling of the polypeptide into an alpha helix
C) The arrangement of multiple polypeptide subunits
D) The interactions between R groups of amino acids
E) The linear sequence of amino acids joined by peptide bonds
✔ Correct Answer: E
EXPERT RATIONALE: The primary structure of a protein refers specifically to the
sequence of amino acids linked together by peptide bonds. This sequence is
determined by the gene and serves as the foundation for all higher levels of protein
structure.
QUESTION 2
,Which bond is responsible for linking amino acids together in a polypeptide
chain?
A) Hydrogen bond
B) Ionic bond
C) Disulfide bond
D) Van der Waals interaction
E) Peptide bond
✔ Correct Answer: E
EXPERT RATIONALE: Peptide bonds are covalent bonds formed between the
carboxyl group of one amino acid and the amino group of the next, releasing water
in a condensation reaction. They form the backbone of all polypeptide chains.
QUESTION 3
What is the term for the process by which a protein loses its three-
dimensional structure?
A) Phosphorylation
B) Translation
C) Glycosylation
D) Hydrolysis
E) Denaturation
✔ Correct Answer: E
EXPERT RATIONALE: Denaturation refers to the unfolding or disruption of a
protein's native three-dimensional structure due to heat, pH changes, chemicals, or
other factors. It typically results in loss of function without breaking peptide bonds.
QUESTION 4
,Which of the following amino acids contains a sulfur atom in its side chain?
A) Alanine
B) Glycine
C) Lysine
D) Phenylalanine
E) Cysteine
✔ Correct Answer: E
EXPERT RATIONALE: Cysteine contains a thiol (-SH) group in its side chain. This
sulfur-containing group is important for forming disulfide bonds that stabilize
protein structure, especially in extracellular proteins.
QUESTION 5
Alpha helices and beta sheets are examples of which level of protein
structure?
A) Primary structure
B) Quaternary structure
C) Tertiary structure
D) Domain structure
E) Secondary structure
✔ Correct Answer: E
EXPERT RATIONALE: Secondary structure refers to the local folding patterns of
the polypeptide backbone stabilized by hydrogen bonds. The alpha helix and beta-
pleated sheet are the two most common forms of secondary structure.
QUESTION 6
, Which of the following is a characteristic of enzyme active sites?
A) They are located far from the substrate binding region
B) They are made up entirely of hydrophobic residues
C) They change irreversibly after every reaction
D) They bind only to cofactors
E) They are specific in shape and chemical nature to their substrates
✔ Correct Answer: E
EXPERT RATIONALE: The active site of an enzyme is a specific region that binds
the substrate through complementary shape, charge, and chemical interactions.
This specificity is key to the enzyme's ability to catalyze particular reactions.
QUESTION 7
What does Km represent in enzyme kinetics?
A) Maximum reaction velocity
B) Total enzyme concentration
C) Product inhibition constant
D) Activation energy of the reaction
E) The substrate concentration at which reaction velocity is half of Vmax
✔ Correct Answer: E
EXPERT RATIONALE: Km (Michaelis constant) is the substrate concentration at
which the reaction velocity is half the maximum (Vmax). A low Km indicates high
affinity between enzyme and substrate, while a high Km indicates low affinity.
QUESTION 8
