, BIOL 101 MODULE 3 EXAM
Essential Biology I w/Lab
Portage Learning
100-Question Practice Examination
2026/2027 Edition
BIOL 101 Module 3 Exam | Essential Biology I w/Lab | Portage Learning | Q
& A | 2026/2027 Edition (PDF)
1. A cell combines two small molecules into a larger molecule and releases water. Which reaction
type best describes this process?
A) Hydrolysis reaction
B) Dehydration reaction
C) Reduction only
D) Fermentation
Correct Answer: B) Dehydration reaction
Rationale: A dehydration reaction joins smaller molecules by removing water as a new covalent bond forms.
Hydrolysis does the opposite by adding water to break a bond. Fermentation is an energy pathway, not a general
bond-forming reaction, and reduction refers specifically to electron gain rather than water loss.
2. A digestive enzyme breaks a polymer into monomers by adding water across covalent bonds.
What type of reaction is occurring?
A) Dehydration
B) Oxidation without bond cleavage
C) Hydrolysis
D) Chemiosmosis
Correct Answer: C) Hydrolysis
Rationale: Hydrolysis uses water to cleave covalent bonds, converting a larger molecule into smaller units.
Dehydration reactions remove water while forming bonds. Oxidation concerns electron loss, and chemiosmosis
describes ion-driven ATP synthesis rather than the enzymatic breakdown of polymers by water addition.
3. Which statement most accurately defines metabolism?
A) The movement of oxygen across membranes
B) Only the reactions that synthesize macromolecules
C) The sum of all chemical reactions occurring in an organism or cell
D) Only the reactions that release ATP
Correct Answer: C) The sum of all chemical reactions occurring in an organism or cell
Rationale: Metabolism includes both constructive and degradative biochemical reactions. Catabolic reactions
break molecules down and often release usable energy, whereas anabolic reactions build larger molecules and
BIOL 101 Module 3 Practice Examination | 2026/2027 Edition Page 1
, usually require energy. Restricting metabolism to only one of these categories omits a major portion of cellular
chemistry.
4. A pathway uses ATP to assemble amino acids into a protein. This pathway is primarily classified
as:
A) Catabolic
B) Oxidative phosphorylation
C) Anabolic
D) Fermentative
Correct Answer: C) Anabolic
Rationale: Anabolic pathways build complex molecules from simpler precursors and generally require an energy
input. Protein synthesis is therefore anabolic. Catabolic pathways break molecules down, fermentation
regenerates electron carriers under oxygen-limited conditions, and oxidative phosphorylation is specifically
mitochondrial ATP generation driven by electron transport.
5. Cellular respiration breaks glucose into smaller molecules while capturing released energy. This is
best classified as:
A) Catabolic metabolism
B) A dehydration synthesis pathway only
C) A purely structural process
D) Anabolic metabolism
Correct Answer: A) Catabolic metabolism
Rationale: Cellular respiration is catabolic because it degrades an energy-rich molecule into smaller products
while conserving part of the released energy in ATP and reduced electron carriers. Anabolism moves in the
opposite direction. The pathway includes several reaction types and is not merely structural or a single
dehydration process.
6. In a redox reaction, a substrate loses electrons. What has happened to that substrate?
A) It has undergone hydrolysis only
B) It has been phosphorylated necessarily
C) It has been oxidized
D) It has been reduced
Correct Answer: C) It has been oxidized
Rationale: Oxidation is the loss of electrons, whereas reduction is the gain of electrons. Redox partners change
together because electrons lost by one species are accepted by another. Hydrolysis and phosphorylation may
occur in metabolism, but neither is implied solely by the loss of electrons.
7. NAD+ accepts electrons and hydrogen during a metabolic reaction. Which product is formed?
A) Pyruvate kinase
B) NADH
C) ATP synthase
D) FAD
BIOL 101 Module 3 Practice Examination | 2026/2027 Edition Page 2
Essential Biology I w/Lab
Portage Learning
100-Question Practice Examination
2026/2027 Edition
BIOL 101 Module 3 Exam | Essential Biology I w/Lab | Portage Learning | Q
& A | 2026/2027 Edition (PDF)
1. A cell combines two small molecules into a larger molecule and releases water. Which reaction
type best describes this process?
A) Hydrolysis reaction
B) Dehydration reaction
C) Reduction only
D) Fermentation
Correct Answer: B) Dehydration reaction
Rationale: A dehydration reaction joins smaller molecules by removing water as a new covalent bond forms.
Hydrolysis does the opposite by adding water to break a bond. Fermentation is an energy pathway, not a general
bond-forming reaction, and reduction refers specifically to electron gain rather than water loss.
2. A digestive enzyme breaks a polymer into monomers by adding water across covalent bonds.
What type of reaction is occurring?
A) Dehydration
B) Oxidation without bond cleavage
C) Hydrolysis
D) Chemiosmosis
Correct Answer: C) Hydrolysis
Rationale: Hydrolysis uses water to cleave covalent bonds, converting a larger molecule into smaller units.
Dehydration reactions remove water while forming bonds. Oxidation concerns electron loss, and chemiosmosis
describes ion-driven ATP synthesis rather than the enzymatic breakdown of polymers by water addition.
3. Which statement most accurately defines metabolism?
A) The movement of oxygen across membranes
B) Only the reactions that synthesize macromolecules
C) The sum of all chemical reactions occurring in an organism or cell
D) Only the reactions that release ATP
Correct Answer: C) The sum of all chemical reactions occurring in an organism or cell
Rationale: Metabolism includes both constructive and degradative biochemical reactions. Catabolic reactions
break molecules down and often release usable energy, whereas anabolic reactions build larger molecules and
BIOL 101 Module 3 Practice Examination | 2026/2027 Edition Page 1
, usually require energy. Restricting metabolism to only one of these categories omits a major portion of cellular
chemistry.
4. A pathway uses ATP to assemble amino acids into a protein. This pathway is primarily classified
as:
A) Catabolic
B) Oxidative phosphorylation
C) Anabolic
D) Fermentative
Correct Answer: C) Anabolic
Rationale: Anabolic pathways build complex molecules from simpler precursors and generally require an energy
input. Protein synthesis is therefore anabolic. Catabolic pathways break molecules down, fermentation
regenerates electron carriers under oxygen-limited conditions, and oxidative phosphorylation is specifically
mitochondrial ATP generation driven by electron transport.
5. Cellular respiration breaks glucose into smaller molecules while capturing released energy. This is
best classified as:
A) Catabolic metabolism
B) A dehydration synthesis pathway only
C) A purely structural process
D) Anabolic metabolism
Correct Answer: A) Catabolic metabolism
Rationale: Cellular respiration is catabolic because it degrades an energy-rich molecule into smaller products
while conserving part of the released energy in ATP and reduced electron carriers. Anabolism moves in the
opposite direction. The pathway includes several reaction types and is not merely structural or a single
dehydration process.
6. In a redox reaction, a substrate loses electrons. What has happened to that substrate?
A) It has undergone hydrolysis only
B) It has been phosphorylated necessarily
C) It has been oxidized
D) It has been reduced
Correct Answer: C) It has been oxidized
Rationale: Oxidation is the loss of electrons, whereas reduction is the gain of electrons. Redox partners change
together because electrons lost by one species are accepted by another. Hydrolysis and phosphorylation may
occur in metabolism, but neither is implied solely by the loss of electrons.
7. NAD+ accepts electrons and hydrogen during a metabolic reaction. Which product is formed?
A) Pyruvate kinase
B) NADH
C) ATP synthase
D) FAD
BIOL 101 Module 3 Practice Examination | 2026/2027 Edition Page 2
