PORTAGE LEARNING
Bachelor of Science in Biology (BS)
BIOL 271 — Microbiology
Academic Year: 2026/2027
Module 2 Exam Review — Complete Question Bank
Portage Learning — Rigorous & Competency-Based
Question 1
What are preformed chemicals?
A. Chemicals synthesized by the cell
B. Chemicals that already exist in the environment
C. Chemicals produced during metabolism
D. Chemicals found only in living organisms
CORRECT ANSWER B. Chemicals that already exist in the environment
Rationale
Preformed chemicals are organic or inorganic molecules that already exist in the
environment and can be used by organisms as energy sources. Chemotrophs derive energy
from these molecules.
, Question 2
What is the effect of enzymes on a chemical reaction?
A. Decrease the rate of the chemical reaction
B. Increase the rate of the chemical reaction
C. Have no effect on the rate
D. Reverse the reaction
CORRECT ANSWER B. Increase the rate of the chemical reaction
Rationale
Enzymes increase the rate of chemical reactions by lowering the activation energy. They are
biological catalysts that accelerate reactions without being consumed in the process.
Question 3
What is the starting source in order for microbes to produce ATP?
A. Electrons
B. Protons
C. Neutrons
D. Photons
CORRECT ANSWER A. Electrons
Rationale
Electrons are the starting source for ATP production in microbes. Energy is extracted from
nutrients by removing electrons (oxidation) and transferring them through electron
transport chains to generate ATP.
, Question 4
What is the result if a phosphate group from ATP is removed?
A. AMP or adenosine monophosphate
B. ADP or adenosine diphosphate
C. Glucose
D. NADH
CORRECT ANSWER B. ADP or adenosine diphosphate
Rationale
When ATP loses a phosphate group through hydrolysis, it becomes ADP (Adenosine
Diphosphate). This reaction releases energy that can be used for cellular work.
Question 5
True or False: Microbes can be classified depending on where their source of carbon
comes from.
A. True
B. False
CORRECT ANSWER A. True
Rationale
Microbes are classified based on carbon source: heterotrophs (organic carbon) and
autotrophs (inorganic carbon, CO₂). This classification is fundamental to microbial ecology.
, Question 6
True or False: Cellular reactions phosphorylate ATP to form ADP.
A. True
B. False
CORRECT ANSWER B. False
Rationale
Phosphorylation is the addition of a phosphate group. The conversion of ATP to ADP is
dephosphorylation (removal of phosphate), not phosphorylation.
Question 7
What is the electron transport system also referred to as?
A. Krebs cycle
B. ETC, electron transport chain
C. Glycolysis
D. Fermentation
CORRECT ANSWER B. ETC, electron transport chain
Rationale
The electron transport system is also called the electron transport chain (ETC), referring to
the series of electron carriers embedded in the membrane.
Bachelor of Science in Biology (BS)
BIOL 271 — Microbiology
Academic Year: 2026/2027
Module 2 Exam Review — Complete Question Bank
Portage Learning — Rigorous & Competency-Based
Question 1
What are preformed chemicals?
A. Chemicals synthesized by the cell
B. Chemicals that already exist in the environment
C. Chemicals produced during metabolism
D. Chemicals found only in living organisms
CORRECT ANSWER B. Chemicals that already exist in the environment
Rationale
Preformed chemicals are organic or inorganic molecules that already exist in the
environment and can be used by organisms as energy sources. Chemotrophs derive energy
from these molecules.
, Question 2
What is the effect of enzymes on a chemical reaction?
A. Decrease the rate of the chemical reaction
B. Increase the rate of the chemical reaction
C. Have no effect on the rate
D. Reverse the reaction
CORRECT ANSWER B. Increase the rate of the chemical reaction
Rationale
Enzymes increase the rate of chemical reactions by lowering the activation energy. They are
biological catalysts that accelerate reactions without being consumed in the process.
Question 3
What is the starting source in order for microbes to produce ATP?
A. Electrons
B. Protons
C. Neutrons
D. Photons
CORRECT ANSWER A. Electrons
Rationale
Electrons are the starting source for ATP production in microbes. Energy is extracted from
nutrients by removing electrons (oxidation) and transferring them through electron
transport chains to generate ATP.
, Question 4
What is the result if a phosphate group from ATP is removed?
A. AMP or adenosine monophosphate
B. ADP or adenosine diphosphate
C. Glucose
D. NADH
CORRECT ANSWER B. ADP or adenosine diphosphate
Rationale
When ATP loses a phosphate group through hydrolysis, it becomes ADP (Adenosine
Diphosphate). This reaction releases energy that can be used for cellular work.
Question 5
True or False: Microbes can be classified depending on where their source of carbon
comes from.
A. True
B. False
CORRECT ANSWER A. True
Rationale
Microbes are classified based on carbon source: heterotrophs (organic carbon) and
autotrophs (inorganic carbon, CO₂). This classification is fundamental to microbial ecology.
, Question 6
True or False: Cellular reactions phosphorylate ATP to form ADP.
A. True
B. False
CORRECT ANSWER B. False
Rationale
Phosphorylation is the addition of a phosphate group. The conversion of ATP to ADP is
dephosphorylation (removal of phosphate), not phosphorylation.
Question 7
What is the electron transport system also referred to as?
A. Krebs cycle
B. ETC, electron transport chain
C. Glycolysis
D. Fermentation
CORRECT ANSWER B. ETC, electron transport chain
Rationale
The electron transport system is also called the electron transport chain (ETC), referring to
the series of electron carriers embedded in the membrane.
