Page 1 of 35
BIOL180 – UNIT TEST 3: BIOMOLECULES AND ENZYMES –
PRACTICE EXAM 2026/2027 COMPLETE CURRENT
TESTING QUESTIONS AND CORRECT ANSWERS WITH
DETAILED RATIONALES.
BIOL
Prepare for the BIOL180 Unit Test 3 – Biomolecules and Enzymes Exam with this
focused practice resource designed to reinforce essential biological chemistry
concepts. Use it to review carbohydrates, lipids, proteins, nucleic acids, enzyme
structure and function, and factors that influence enzyme activity. This resource can
help strengthen your understanding, identify areas that may require additional study,
and improve your test readiness. It provides a structured supplement to your
coursework and supports a more confident approach to the BIOL180 assessment.
MULTIPLE CHOICE.
Section 1: Foundations of Biomolecules (Q1–Q15)
1. Which of the following best describes the relationship between
monomers and polymers?
A. Polymers are broken down into monomers through dehydration synthesis.
B. Monomers are joined together to form polymers through hydrolysis.
C. Polymers are large molecules made of repeating monomer subunits joined
by covalent bonds.
D. Monomers are large molecules made of repeating polymer subunits.
Answer: C
Rationale: Polymers are large molecules (e.g., proteins, nucleic acids,
carbohydrates) composed of repeating monomer subunits linked by
covalent bonds. Monomers are joined by dehydration synthesis (removing
water), and polymers are broken down by hydrolysis (adding water).
2. Which of the following is NOT one of the four major classes of biological
macromolecules?
A. Carbohydrates
B. Lipids
, Page 2 of 35
C. Nucleic acids
D. Minerals
Answer: D
Rationale: The four major classes of biological macromolecules are
carbohydrates, lipids, proteins, and nucleic acids. Minerals are inorganic
nutrients, not macromolecules.
3. What type of reaction joins two monomers together by removing a
water molecule?
A. Hydrolysis
B. Dehydration synthesis
C. Oxidation
D. Reduction
Answer: B
Rationale: Dehydration synthesis (condensation) removes a water
molecule to form a covalent bond between two monomers. Hydrolysis
uses water to break bonds.
4. Which of the following best describes hydrolysis?
A. Water is removed to form polymers.
B. Water is added to break chemical bonds.
C. Peptide bonds are strengthened.
D. ATP is always produced.
Answer: B
Rationale: Hydrolysis uses water to break covalent bonds, separating
polymers into their monomers. This is the reverse of dehydration
synthesis.
5. Which element is found in proteins but not always present in
carbohydrates or lipids?
A. Carbon
B. Hydrogen
C. Oxygen
D. Nitrogen
, Page 3 of 35
Answer: D
Rationale: Proteins contain nitrogen as part of their amino groups,
whereas carbohydrates and many lipids consist mainly of carbon,
hydrogen, and oxygen.
6. Which biomolecule provides the greatest amount of energy per gram?
A. Carbohydrates
B. Proteins
C. Nucleic acids
D. Lipids
Answer: D
Rationale: Lipids yield approximately 9 kcal per gram, compared with
about 4 kcal per gram for carbohydrates and proteins.
7. Which class of biomolecules is primarily responsible for storing and
transmitting hereditary information?
A. Carbohydrates
B. Lipids
C. Proteins
D. Nucleic acids
Answer: D
Rationale: Nucleic acids, including DNA and RNA, store, transmit, and
express genetic information.
8. Which of the following is a function of proteins?
A. Long-term energy storage
B. Catalyzing chemical reactions
C. Storing genetic information
D. Forming cell membranes
Answer: B
Rationale: Proteins function as enzymes (catalysts), structural
components, transport molecules, hormones, and more.
9. Which of the following is a function of lipids?
A. Catalyzing chemical reactions
B. Storing genetic information
, Page 4 of 35
C. Long-term energy storage and forming cell membranes
D. Transporting oxygen in the blood
Answer: C
Rationale: Lipids function in long-term energy storage, forming cell
membranes (phospholipids), insulation, and signaling (steroid
hormones).
10. Which of the following is a function of carbohydrates?
A. Storing genetic information
B. Providing immediate energy and structural support
C. Catalyzing chemical reactions
D. Forming cell membranes
Answer: B
Rationale: Carbohydrates provide immediate energy (glucose) and
structural support (cellulose in plants, chitin in fungi).
11. Which of the following is a monosaccharide?
A. Sucrose
B. Glucose
C. Lactose
D. Maltose
Answer: B
Rationale: Glucose is a monosaccharide (single sugar). Sucrose, lactose,
and maltose are disaccharides.
12. Which of the following is a disaccharide?
A. Glucose
B. Fructose
C. Sucrose
D. Glycogen
Answer: C
Rationale: Sucrose (table sugar) is a disaccharide composed of glucose
and fructose. Glucose and fructose are monosaccharides; glycogen is a
polysaccharide.
BIOL180 – UNIT TEST 3: BIOMOLECULES AND ENZYMES –
PRACTICE EXAM 2026/2027 COMPLETE CURRENT
TESTING QUESTIONS AND CORRECT ANSWERS WITH
DETAILED RATIONALES.
BIOL
Prepare for the BIOL180 Unit Test 3 – Biomolecules and Enzymes Exam with this
focused practice resource designed to reinforce essential biological chemistry
concepts. Use it to review carbohydrates, lipids, proteins, nucleic acids, enzyme
structure and function, and factors that influence enzyme activity. This resource can
help strengthen your understanding, identify areas that may require additional study,
and improve your test readiness. It provides a structured supplement to your
coursework and supports a more confident approach to the BIOL180 assessment.
MULTIPLE CHOICE.
Section 1: Foundations of Biomolecules (Q1–Q15)
1. Which of the following best describes the relationship between
monomers and polymers?
A. Polymers are broken down into monomers through dehydration synthesis.
B. Monomers are joined together to form polymers through hydrolysis.
C. Polymers are large molecules made of repeating monomer subunits joined
by covalent bonds.
D. Monomers are large molecules made of repeating polymer subunits.
Answer: C
Rationale: Polymers are large molecules (e.g., proteins, nucleic acids,
carbohydrates) composed of repeating monomer subunits linked by
covalent bonds. Monomers are joined by dehydration synthesis (removing
water), and polymers are broken down by hydrolysis (adding water).
2. Which of the following is NOT one of the four major classes of biological
macromolecules?
A. Carbohydrates
B. Lipids
, Page 2 of 35
C. Nucleic acids
D. Minerals
Answer: D
Rationale: The four major classes of biological macromolecules are
carbohydrates, lipids, proteins, and nucleic acids. Minerals are inorganic
nutrients, not macromolecules.
3. What type of reaction joins two monomers together by removing a
water molecule?
A. Hydrolysis
B. Dehydration synthesis
C. Oxidation
D. Reduction
Answer: B
Rationale: Dehydration synthesis (condensation) removes a water
molecule to form a covalent bond between two monomers. Hydrolysis
uses water to break bonds.
4. Which of the following best describes hydrolysis?
A. Water is removed to form polymers.
B. Water is added to break chemical bonds.
C. Peptide bonds are strengthened.
D. ATP is always produced.
Answer: B
Rationale: Hydrolysis uses water to break covalent bonds, separating
polymers into their monomers. This is the reverse of dehydration
synthesis.
5. Which element is found in proteins but not always present in
carbohydrates or lipids?
A. Carbon
B. Hydrogen
C. Oxygen
D. Nitrogen
, Page 3 of 35
Answer: D
Rationale: Proteins contain nitrogen as part of their amino groups,
whereas carbohydrates and many lipids consist mainly of carbon,
hydrogen, and oxygen.
6. Which biomolecule provides the greatest amount of energy per gram?
A. Carbohydrates
B. Proteins
C. Nucleic acids
D. Lipids
Answer: D
Rationale: Lipids yield approximately 9 kcal per gram, compared with
about 4 kcal per gram for carbohydrates and proteins.
7. Which class of biomolecules is primarily responsible for storing and
transmitting hereditary information?
A. Carbohydrates
B. Lipids
C. Proteins
D. Nucleic acids
Answer: D
Rationale: Nucleic acids, including DNA and RNA, store, transmit, and
express genetic information.
8. Which of the following is a function of proteins?
A. Long-term energy storage
B. Catalyzing chemical reactions
C. Storing genetic information
D. Forming cell membranes
Answer: B
Rationale: Proteins function as enzymes (catalysts), structural
components, transport molecules, hormones, and more.
9. Which of the following is a function of lipids?
A. Catalyzing chemical reactions
B. Storing genetic information
, Page 4 of 35
C. Long-term energy storage and forming cell membranes
D. Transporting oxygen in the blood
Answer: C
Rationale: Lipids function in long-term energy storage, forming cell
membranes (phospholipids), insulation, and signaling (steroid
hormones).
10. Which of the following is a function of carbohydrates?
A. Storing genetic information
B. Providing immediate energy and structural support
C. Catalyzing chemical reactions
D. Forming cell membranes
Answer: B
Rationale: Carbohydrates provide immediate energy (glucose) and
structural support (cellulose in plants, chitin in fungi).
11. Which of the following is a monosaccharide?
A. Sucrose
B. Glucose
C. Lactose
D. Maltose
Answer: B
Rationale: Glucose is a monosaccharide (single sugar). Sucrose, lactose,
and maltose are disaccharides.
12. Which of the following is a disaccharide?
A. Glucose
B. Fructose
C. Sucrose
D. Glycogen
Answer: C
Rationale: Sucrose (table sugar) is a disaccharide composed of glucose
and fructose. Glucose and fructose are monosaccharides; glycogen is a
polysaccharide.
