CHEM 210 Biochemistry Comprehensive
ExaminationModules 1-8 & Final Exam WITH CORRECT
ANSWERS WELL VERIFIED AND DETAILED RATIONALES
2026!
MODULE 1: Foundations of Biochemistry
1. Which of the following is NOT one of the four major classes of biomolecules?
A) Carbohydrates
B) Lipids
C) Nucleic Acids
D) Minerals
E) Proteins
ANSWER: D) Minerals
Rationale: The four major classes of biomolecules are carbohydrates, lipids, nucleic acids, and proteins.
Minerals are inorganic compounds essential for life but not considered biomolecules.
2. The pH of a solution is 3.0. What is the concentration of H+ ions?
A) 1 × 10⁻³ M
B) 1 × 10³ M
C) 3.0 M
D) 1 × 10⁻¹¹ M
E) 1 × 10⁻⁷ M
ANSWER: A) 1 × 10⁻³ M
Rationale: pH = -log[H+]. Therefore, [H+] = 10⁻pH = 10⁻³ = 1 × 10⁻³ M.
,3. Which functional group is represented by -COOH?
A) Alcohol
B) Aldehyde
C) Carboxylic acid
D) Amine
E) Ketone
ANSWER: C) Carboxylic acid
Rationale: The -COOH group is the carboxylic acid functional group. It consists of a carbonyl group (C=O)
attached to a hydroxyl group (-OH).
4. Buffers resist changes in pH by:
A) Absorbing all H+ ions
B) Releasing OH- ions
C) Donating or accepting protons
D) Changing temperature
E) Precipitating solutes
ANSWER: C) Donating or accepting protons
Rationale: Buffers consist of a weak acid and its conjugate base. They can donate protons when pH
increases or accept protons when pH decreases, maintaining relatively constant pH.
5. The Henderson-Hasselbalch equation is:
A) pH = pKa + log([A-]/[HA])
B) pH = pKa - log([A-]/[HA])
C) pH = pKa + log([HA]/[A-])
D) pH = pKb + log([A-]/[HA])
E) pH = pKa + log([H+]/[OH-])
,ANSWER: A) pH = pKa + log([A-]/[HA])
Rationale: The Henderson-Hasselbalch equation relates pH, pKa, and the ratio of conjugate base to acid
concentrations. It is used to calculate pH of buffer solutions.
6. Which bond type is formed by the sharing of electrons between atoms?
A) Ionic bond
B) Hydrogen bond
C) Covalent bond
D) Van der Waals interaction
E) Hydrophobic interaction
ANSWER: C) Covalent bond
Rationale: Covalent bonds involve the sharing of electron pairs between atoms. This is the strongest
type of chemical bond found in biomolecules.
7. Water has a high specific heat due to:
A) Covalent bonds
B) Hydrogen bonds
C) Ionic bonds
D) Van der Waals forces
E) Hydrophobic effects
ANSWER: B) Hydrogen bonds
Rationale: Water's high specific heat results from the extensive hydrogen bonding network. Breaking
these bonds requires significant energy input, allowing water to resist temperature changes.
8. Which of the following is a reducing sugar?
A) Sucrose
B) Starch
C) Cellulose
, D) Glucose
E) Glycogen
ANSWER: D) Glucose
Rationale: Glucose has a free aldehyde group in its open-chain form, making it a reducing sugar.
Sucrose, starch, cellulose, and glycogen do not have free reducing ends.
9. The building blocks of proteins are:
A) Nucleotides
B) Monosaccharides
C) Amino acids
D) Fatty acids
E) Glycerol
ANSWER: C) Amino acids
Rationale: Proteins are polymers composed of amino acid monomers linked by peptide bonds. There are
20 standard amino acids used in protein synthesis.
10. Which level of protein structure refers to the linear sequence of amino acids?
A) Primary structure
B) Secondary structure
C) Tertiary structure
D) Quaternary structure
E) All of the above
ANSWER: A) Primary structure
Rationale: Primary structure is the linear sequence of amino acids in a polypeptide chain. It determines
higher levels of protein structure.
11. The α-helix and β-pleated sheet are examples of:
ExaminationModules 1-8 & Final Exam WITH CORRECT
ANSWERS WELL VERIFIED AND DETAILED RATIONALES
2026!
MODULE 1: Foundations of Biochemistry
1. Which of the following is NOT one of the four major classes of biomolecules?
A) Carbohydrates
B) Lipids
C) Nucleic Acids
D) Minerals
E) Proteins
ANSWER: D) Minerals
Rationale: The four major classes of biomolecules are carbohydrates, lipids, nucleic acids, and proteins.
Minerals are inorganic compounds essential for life but not considered biomolecules.
2. The pH of a solution is 3.0. What is the concentration of H+ ions?
A) 1 × 10⁻³ M
B) 1 × 10³ M
C) 3.0 M
D) 1 × 10⁻¹¹ M
E) 1 × 10⁻⁷ M
ANSWER: A) 1 × 10⁻³ M
Rationale: pH = -log[H+]. Therefore, [H+] = 10⁻pH = 10⁻³ = 1 × 10⁻³ M.
,3. Which functional group is represented by -COOH?
A) Alcohol
B) Aldehyde
C) Carboxylic acid
D) Amine
E) Ketone
ANSWER: C) Carboxylic acid
Rationale: The -COOH group is the carboxylic acid functional group. It consists of a carbonyl group (C=O)
attached to a hydroxyl group (-OH).
4. Buffers resist changes in pH by:
A) Absorbing all H+ ions
B) Releasing OH- ions
C) Donating or accepting protons
D) Changing temperature
E) Precipitating solutes
ANSWER: C) Donating or accepting protons
Rationale: Buffers consist of a weak acid and its conjugate base. They can donate protons when pH
increases or accept protons when pH decreases, maintaining relatively constant pH.
5. The Henderson-Hasselbalch equation is:
A) pH = pKa + log([A-]/[HA])
B) pH = pKa - log([A-]/[HA])
C) pH = pKa + log([HA]/[A-])
D) pH = pKb + log([A-]/[HA])
E) pH = pKa + log([H+]/[OH-])
,ANSWER: A) pH = pKa + log([A-]/[HA])
Rationale: The Henderson-Hasselbalch equation relates pH, pKa, and the ratio of conjugate base to acid
concentrations. It is used to calculate pH of buffer solutions.
6. Which bond type is formed by the sharing of electrons between atoms?
A) Ionic bond
B) Hydrogen bond
C) Covalent bond
D) Van der Waals interaction
E) Hydrophobic interaction
ANSWER: C) Covalent bond
Rationale: Covalent bonds involve the sharing of electron pairs between atoms. This is the strongest
type of chemical bond found in biomolecules.
7. Water has a high specific heat due to:
A) Covalent bonds
B) Hydrogen bonds
C) Ionic bonds
D) Van der Waals forces
E) Hydrophobic effects
ANSWER: B) Hydrogen bonds
Rationale: Water's high specific heat results from the extensive hydrogen bonding network. Breaking
these bonds requires significant energy input, allowing water to resist temperature changes.
8. Which of the following is a reducing sugar?
A) Sucrose
B) Starch
C) Cellulose
, D) Glucose
E) Glycogen
ANSWER: D) Glucose
Rationale: Glucose has a free aldehyde group in its open-chain form, making it a reducing sugar.
Sucrose, starch, cellulose, and glycogen do not have free reducing ends.
9. The building blocks of proteins are:
A) Nucleotides
B) Monosaccharides
C) Amino acids
D) Fatty acids
E) Glycerol
ANSWER: C) Amino acids
Rationale: Proteins are polymers composed of amino acid monomers linked by peptide bonds. There are
20 standard amino acids used in protein synthesis.
10. Which level of protein structure refers to the linear sequence of amino acids?
A) Primary structure
B) Secondary structure
C) Tertiary structure
D) Quaternary structure
E) All of the above
ANSWER: A) Primary structure
Rationale: Primary structure is the linear sequence of amino acids in a polypeptide chain. It determines
higher levels of protein structure.
11. The α-helix and β-pleated sheet are examples of:
