BIO 171 Module 2 Exam(Questions & Answers)- Microbiology-
Portage Learning(New-2021/2022)
BIO 171 Module 2 Exam — Alternate Form (100 Questions, ABCD + Rationales)
Section 1: Metabolism Basics (1–15)
Q1. Which statement best defines metabolism?
A) Breakdown of glucose only
B) Synthesis of proteins only
C) All chemical reactions in a cell
D) Only reactions that produce ATP
Answer: C
Rationale: Metabolism includes both catabolism (breakdown) and anabolism
(synthesis).
Q2. True or False (ABCD form): Metabolism only occurs in the presence of
oxygen.
A) True
B) False, because metabolism occurs with or without oxygen
C) True, only in animals
D) False, only plants have metabolism
Answer: B
Rationale: Anaerobic organisms carry out metabolism without oxygen.
Q3. True or False (ABCD): All enzymes are proteins.
A) True, always
B) False, some enzymes are RNA (ribozymes)
C) True, only in eukaryotes
D) False, all enzymes are lipids
Answer: B
Rationale: Most enzymes are proteins, but ribozymes (catalytic RNA) exist.
,Q4. The energy needed to start a chemical reaction is called:
A) Free energy
B) Activation energy
C) Kinetic energy
D) Potential energy
Answer: B
Rationale: Enzymes lower activation energy.
Q5. Which of the following is NOT a characteristic of enzymes?
A) They are specific to substrates
B) They are consumed in reactions
C) They lower activation energy
D) They are affected by pH
Answer: B
Rationale: Enzymes are not consumed; they are recycled.
Q6. A coenzyme is a type of:
A) Metal ion
B) Organic cofactor (e.g., vitamins)
C) Enzyme
D) Substrate
Answer: B
Rationale: Coenzymes are organic molecules (NAD⁺, FAD, CoA).
Q7. Which of the following is a coenzyme?
A) Mg²⁺
B) Zn²⁺
C) NAD⁺
D) Ca²⁺
Answer: C
Rationale: NAD⁺ is an organic coenzyme; metals are cofactors.
Q8. An apoenzyme is:
A) The active enzyme with cofactor
B) The inactive enzyme without cofactor
, C) A denatured enzyme
D) An enzyme that works in reverse
Answer: B
Rationale: Apoenzyme + cofactor = holoenzyme.
Q9. Which temperature would most likely denature most human enzymes?
A) 0°C
B) 25°C
C) 37°C
D) 65°C
Answer: D
Rationale: High heat denatures proteins; 65°C is above physiological range.
Q10. At very low temperatures, enzyme activity:
A) Increases
B) Decreases due to slowed molecular motion
C) Remains the same
D) Becomes irreversible
Answer: B
Rationale: Cold slows molecule movement, reducing collisions.
Q11. The lock-and-key model refers to:
A) Enzyme denaturation
B) Enzyme-substrate specificity
C) ATP synthesis
D) Fermentation
Answer: B
Rationale: The active site (lock) matches specific substrate (key).
Q12. Induced fit means:
A) Enzyme changes shape to bind substrate
B) Substrate changes shape to fit enzyme
C) Enzyme destroys substrate
D) No shape change occurs
Portage Learning(New-2021/2022)
BIO 171 Module 2 Exam — Alternate Form (100 Questions, ABCD + Rationales)
Section 1: Metabolism Basics (1–15)
Q1. Which statement best defines metabolism?
A) Breakdown of glucose only
B) Synthesis of proteins only
C) All chemical reactions in a cell
D) Only reactions that produce ATP
Answer: C
Rationale: Metabolism includes both catabolism (breakdown) and anabolism
(synthesis).
Q2. True or False (ABCD form): Metabolism only occurs in the presence of
oxygen.
A) True
B) False, because metabolism occurs with or without oxygen
C) True, only in animals
D) False, only plants have metabolism
Answer: B
Rationale: Anaerobic organisms carry out metabolism without oxygen.
Q3. True or False (ABCD): All enzymes are proteins.
A) True, always
B) False, some enzymes are RNA (ribozymes)
C) True, only in eukaryotes
D) False, all enzymes are lipids
Answer: B
Rationale: Most enzymes are proteins, but ribozymes (catalytic RNA) exist.
,Q4. The energy needed to start a chemical reaction is called:
A) Free energy
B) Activation energy
C) Kinetic energy
D) Potential energy
Answer: B
Rationale: Enzymes lower activation energy.
Q5. Which of the following is NOT a characteristic of enzymes?
A) They are specific to substrates
B) They are consumed in reactions
C) They lower activation energy
D) They are affected by pH
Answer: B
Rationale: Enzymes are not consumed; they are recycled.
Q6. A coenzyme is a type of:
A) Metal ion
B) Organic cofactor (e.g., vitamins)
C) Enzyme
D) Substrate
Answer: B
Rationale: Coenzymes are organic molecules (NAD⁺, FAD, CoA).
Q7. Which of the following is a coenzyme?
A) Mg²⁺
B) Zn²⁺
C) NAD⁺
D) Ca²⁺
Answer: C
Rationale: NAD⁺ is an organic coenzyme; metals are cofactors.
Q8. An apoenzyme is:
A) The active enzyme with cofactor
B) The inactive enzyme without cofactor
, C) A denatured enzyme
D) An enzyme that works in reverse
Answer: B
Rationale: Apoenzyme + cofactor = holoenzyme.
Q9. Which temperature would most likely denature most human enzymes?
A) 0°C
B) 25°C
C) 37°C
D) 65°C
Answer: D
Rationale: High heat denatures proteins; 65°C is above physiological range.
Q10. At very low temperatures, enzyme activity:
A) Increases
B) Decreases due to slowed molecular motion
C) Remains the same
D) Becomes irreversible
Answer: B
Rationale: Cold slows molecule movement, reducing collisions.
Q11. The lock-and-key model refers to:
A) Enzyme denaturation
B) Enzyme-substrate specificity
C) ATP synthesis
D) Fermentation
Answer: B
Rationale: The active site (lock) matches specific substrate (key).
Q12. Induced fit means:
A) Enzyme changes shape to bind substrate
B) Substrate changes shape to fit enzyme
C) Enzyme destroys substrate
D) No shape change occurs
