BIOD 171 Module 2 Exam – Microbiology (Portage Learning) (2026)
Actual Questions with Verified Answers | Take & Pass the Exam
Questions 1–70+
1. True or False: Metabolism is a controlled set of biochemical reactions that occur in living
organisms in order to maintain life.
A) True
B) False
Answer A: True
Rationale: Metabolism encompasses all chemical reactions in living organisms that sustain life, including
energy conversion and biosynthesis.
2. True or False: Enzymes are polysaccharides that catalyze chemical reactions.
A) True
B) False
Answer B: False
Rationale: Enzymes are proteins, not polysaccharides, that function as biological catalysts to speed up
chemical reactions.
3. True or False: Enzymes slow down chemical reactions to conserve energy.
A) True
B) False
Answer B: False
Rationale: Enzymes accelerate chemical reactions by lowering activation energy; slowing reactions would
be energetically disadvantageous.
4. What is the primary source of energy for cellular metabolism?
A) Oxygen
,B) Glucose
C) Water
D) Nitrogen
Answer B: Glucose
Rationale: Glucose is the primary carbohydrate broken down through glycolysis and cellular respiration to
produce ATP.
5. Which molecule is the primary energy currency of cells?
A) ADP
B) ATP
C) NAD⁺
D) FAD
Answer B: ATP
Rationale: ATP stores and releases energy via its high-energy phosphate bonds, powering cellular work.
6. What role do enzymes play in metabolism?
A) Store energy
B) Catalyze chemical reactions
C) Transport oxygen
D) Synthesize DNA
Answer B: Catalyze chemical reactions
Rationale: Enzymes lower the activation energy required for reactions, enabling them to proceed rapidly
under physiological conditions.
7. What is a cofactor? Provide a general example.
A) A small chemical component that assists an enzyme during catalysis; example: metal ions
B) A protein that catalyzes reactions
C) A substrate that binds to an enzyme
D) A product of an enzymatic reaction
Answer A: A small chemical component that assists an enzyme during catalysis; example: metal ions
Rationale: Cofactors (e.g., metal ions like Mg²⁺, Zn²⁺) are non-protein molecules that help enzymes function
properly.
, 8. What is the main product of glycolysis?
A) Acetyl-CoA
B) Pyruvate
C) Lactate
D) Ethanol
Answer B: Pyruvate
Rationale: Glycolysis converts one glucose molecule into two pyruvate molecules, yielding a net of 2 ATP.
9. In which cellular compartment does the Krebs cycle occur in eukaryotes?
A) Cytoplasm
B) Mitochondrial matrix
C) Inner mitochondrial membrane
D) Nucleus
Answer B: Mitochondrial matrix
Rationale: The Krebs (citric acid) cycle takes place in the mitochondrial matrix in eukaryotic cells.
10. What is the final electron acceptor in aerobic respiration?
A) NAD⁺
B) Oxygen
C) Carbon dioxide
D) Water
Answer B: Oxygen
Rationale: Oxygen serves as the final electron acceptor in the electron transport chain, combining with
electrons and protons to form water.
11. Which process generates the most ATP during cellular respiration?
A) Glycolysis
B) Krebs cycle
C) Electron transport chain (ETC)
D) Fermentation
Answer C: Electron transport chain (ETC)
Rationale: The ETC produces up to 34 ATP molecules per glucose, far more than glycolysis or the Krebs cycle.
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Actual Questions with Verified Answers | Take & Pass the Exam
Questions 1–70+
1. True or False: Metabolism is a controlled set of biochemical reactions that occur in living
organisms in order to maintain life.
A) True
B) False
Answer A: True
Rationale: Metabolism encompasses all chemical reactions in living organisms that sustain life, including
energy conversion and biosynthesis.
2. True or False: Enzymes are polysaccharides that catalyze chemical reactions.
A) True
B) False
Answer B: False
Rationale: Enzymes are proteins, not polysaccharides, that function as biological catalysts to speed up
chemical reactions.
3. True or False: Enzymes slow down chemical reactions to conserve energy.
A) True
B) False
Answer B: False
Rationale: Enzymes accelerate chemical reactions by lowering activation energy; slowing reactions would
be energetically disadvantageous.
4. What is the primary source of energy for cellular metabolism?
A) Oxygen
,B) Glucose
C) Water
D) Nitrogen
Answer B: Glucose
Rationale: Glucose is the primary carbohydrate broken down through glycolysis and cellular respiration to
produce ATP.
5. Which molecule is the primary energy currency of cells?
A) ADP
B) ATP
C) NAD⁺
D) FAD
Answer B: ATP
Rationale: ATP stores and releases energy via its high-energy phosphate bonds, powering cellular work.
6. What role do enzymes play in metabolism?
A) Store energy
B) Catalyze chemical reactions
C) Transport oxygen
D) Synthesize DNA
Answer B: Catalyze chemical reactions
Rationale: Enzymes lower the activation energy required for reactions, enabling them to proceed rapidly
under physiological conditions.
7. What is a cofactor? Provide a general example.
A) A small chemical component that assists an enzyme during catalysis; example: metal ions
B) A protein that catalyzes reactions
C) A substrate that binds to an enzyme
D) A product of an enzymatic reaction
Answer A: A small chemical component that assists an enzyme during catalysis; example: metal ions
Rationale: Cofactors (e.g., metal ions like Mg²⁺, Zn²⁺) are non-protein molecules that help enzymes function
properly.
, 8. What is the main product of glycolysis?
A) Acetyl-CoA
B) Pyruvate
C) Lactate
D) Ethanol
Answer B: Pyruvate
Rationale: Glycolysis converts one glucose molecule into two pyruvate molecules, yielding a net of 2 ATP.
9. In which cellular compartment does the Krebs cycle occur in eukaryotes?
A) Cytoplasm
B) Mitochondrial matrix
C) Inner mitochondrial membrane
D) Nucleus
Answer B: Mitochondrial matrix
Rationale: The Krebs (citric acid) cycle takes place in the mitochondrial matrix in eukaryotic cells.
10. What is the final electron acceptor in aerobic respiration?
A) NAD⁺
B) Oxygen
C) Carbon dioxide
D) Water
Answer B: Oxygen
Rationale: Oxygen serves as the final electron acceptor in the electron transport chain, combining with
electrons and protons to form water.
11. Which process generates the most ATP during cellular respiration?
A) Glycolysis
B) Krebs cycle
C) Electron transport chain (ETC)
D) Fermentation
Answer C: Electron transport chain (ETC)
Rationale: The ETC produces up to 34 ATP molecules per glucose, far more than glycolysis or the Krebs cycle.
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