2026 BIOD 101 Module 4 Final Exam – 2026 | Portage Learning | Complete
Verified Q&As + Review Guide
The final 100-question segment for Module 4. This 2026 update dives into C3, C4, and
CAM plants, Photorespiration, Electrochemical Gradients, Allosteric Regulation, and the Total
ATP Accounting of aerobic vs. anaerobic pathways. Critical for students aiming for high
scores on the Portage Biology Final.
1. The First Law of Thermodynamics states that:
A. Energy increases over time.
B. Energy cannot be created or destroyed, only transformed.
C. Entropy is always decreasing.
D. Energy is lost as cold.
Rationale: The First Law (Conservation of Energy) means the total amount of energy
in the universe remains constant.
2. Which molecule is considered the "energy currency" of the cell?
A. Glucose
B. DNA
C. ATP (Adenosine Triphosphate)
D. Protein
Rationale: ATP stores energy in its high-energy phosphate bonds and releases it when
the third phosphate is removed.
3. Enzymes speed up chemical reactions by:
A. Increasing the temperature.
B. Lowering the activation energy.
C. Adding more reactants.
D. Changing the product.
Rationale: Enzymes are biological catalysts that lower the energy "barrier" required for
a reaction to start.
4. Where in the cell does Glycolysis take place?
A. Mitochondria
B. Cytoplasm
C. Nucleus
D. Ribosome
Rationale: Glycolysis is the first step of cellular respiration and occurs in the cytosol
(cytoplasm) of all cells.
,5. What is the net gain of ATP molecules produced during Glycolysis?
A. 0
B. 2
C. 4
D. 36
Rationale: While 4 ATP are produced, 2 are consumed to start the process, leaving
a net gain of 2 ATP.
6. Which stage of cellular respiration produces the most ATP?
A. Glycolysis
B. Krebs Cycle
C. Electron Transport Chain (Oxidative Phosphorylation)
D. Fermentation
Rationale: The Electron Transport Chain produces approximately 32–34 ATP per
glucose molecule.
7. In the absence of oxygen, yeast cells perform:
A. Aerobic respiration
B. Alcoholic fermentation
C. Lactic acid fermentation
D. Photosynthesis
Rationale: Yeast converts pyruvate into ethanol and CO2 to regenerate NAD+ when
oxygen is unavailable.
8. What is the primary pigment used by plants to capture light energy?
A. Carotenoid
B. Chlorophyll
C. Hemoglobin
D. Melanin
Rationale: Chlorophyll absorbs blue and red light while reflecting green light, giving
plants their color.
9. The "Active Site" of an enzyme is the location where:
A. The product is destroyed.
B. The substrate binds.
C. ATP is produced.
D. DNA is replicated.
Rationale: The Active Site is a specifically shaped "pocket" where the substrate fits to
undergo a reaction.
, 10. Which of the following is a byproduct of photosynthesis?
A. Carbon Dioxide
B. Oxygen
C. Water
D. Glucose
Rationale: While glucose is the main product, Oxygen is released as a waste
byproduct into the atmosphere.
11. An "Exergonic" reaction is one that:
A. Absorbs energy.
B. Releases energy.
C. Requires a vacuum.
D. Only happens in plants.
Rationale: Exergonic reactions (like cellular respiration) release free energy into the
surroundings.
12. The Citric Acid Cycle (Krebs Cycle) takes place in the:
A. Cytoplasm
B. Mitochondrial Matrix
C. Chloroplast
D. Rough ER
Rationale: Pyruvate enters the matrix to be fully oxidized into Carbon Dioxide.
13. What happens to an enzyme if the temperature or pH is outside its optimal
range?
A. It works faster.
B. It becomes denatured (loses its shape).
C. It turns into a lipid.
D. It duplicates.
Rationale: Denaturation breaks the chemical bonds that hold the enzyme's 3D shape,
making it non-functional.
14. The "Light-Dependent" reactions of photosynthesis occur in the:
A. Stroma
B. Thylakoid membranes
C. Mitochondria
D. Nucleus
Rationale: The thylakoids contain the chlorophyll needed to capture solar energy.
15. Which molecule acts as the final electron acceptor in the Electron Transport
Chain?
Verified Q&As + Review Guide
The final 100-question segment for Module 4. This 2026 update dives into C3, C4, and
CAM plants, Photorespiration, Electrochemical Gradients, Allosteric Regulation, and the Total
ATP Accounting of aerobic vs. anaerobic pathways. Critical for students aiming for high
scores on the Portage Biology Final.
1. The First Law of Thermodynamics states that:
A. Energy increases over time.
B. Energy cannot be created or destroyed, only transformed.
C. Entropy is always decreasing.
D. Energy is lost as cold.
Rationale: The First Law (Conservation of Energy) means the total amount of energy
in the universe remains constant.
2. Which molecule is considered the "energy currency" of the cell?
A. Glucose
B. DNA
C. ATP (Adenosine Triphosphate)
D. Protein
Rationale: ATP stores energy in its high-energy phosphate bonds and releases it when
the third phosphate is removed.
3. Enzymes speed up chemical reactions by:
A. Increasing the temperature.
B. Lowering the activation energy.
C. Adding more reactants.
D. Changing the product.
Rationale: Enzymes are biological catalysts that lower the energy "barrier" required for
a reaction to start.
4. Where in the cell does Glycolysis take place?
A. Mitochondria
B. Cytoplasm
C. Nucleus
D. Ribosome
Rationale: Glycolysis is the first step of cellular respiration and occurs in the cytosol
(cytoplasm) of all cells.
,5. What is the net gain of ATP molecules produced during Glycolysis?
A. 0
B. 2
C. 4
D. 36
Rationale: While 4 ATP are produced, 2 are consumed to start the process, leaving
a net gain of 2 ATP.
6. Which stage of cellular respiration produces the most ATP?
A. Glycolysis
B. Krebs Cycle
C. Electron Transport Chain (Oxidative Phosphorylation)
D. Fermentation
Rationale: The Electron Transport Chain produces approximately 32–34 ATP per
glucose molecule.
7. In the absence of oxygen, yeast cells perform:
A. Aerobic respiration
B. Alcoholic fermentation
C. Lactic acid fermentation
D. Photosynthesis
Rationale: Yeast converts pyruvate into ethanol and CO2 to regenerate NAD+ when
oxygen is unavailable.
8. What is the primary pigment used by plants to capture light energy?
A. Carotenoid
B. Chlorophyll
C. Hemoglobin
D. Melanin
Rationale: Chlorophyll absorbs blue and red light while reflecting green light, giving
plants their color.
9. The "Active Site" of an enzyme is the location where:
A. The product is destroyed.
B. The substrate binds.
C. ATP is produced.
D. DNA is replicated.
Rationale: The Active Site is a specifically shaped "pocket" where the substrate fits to
undergo a reaction.
, 10. Which of the following is a byproduct of photosynthesis?
A. Carbon Dioxide
B. Oxygen
C. Water
D. Glucose
Rationale: While glucose is the main product, Oxygen is released as a waste
byproduct into the atmosphere.
11. An "Exergonic" reaction is one that:
A. Absorbs energy.
B. Releases energy.
C. Requires a vacuum.
D. Only happens in plants.
Rationale: Exergonic reactions (like cellular respiration) release free energy into the
surroundings.
12. The Citric Acid Cycle (Krebs Cycle) takes place in the:
A. Cytoplasm
B. Mitochondrial Matrix
C. Chloroplast
D. Rough ER
Rationale: Pyruvate enters the matrix to be fully oxidized into Carbon Dioxide.
13. What happens to an enzyme if the temperature or pH is outside its optimal
range?
A. It works faster.
B. It becomes denatured (loses its shape).
C. It turns into a lipid.
D. It duplicates.
Rationale: Denaturation breaks the chemical bonds that hold the enzyme's 3D shape,
making it non-functional.
14. The "Light-Dependent" reactions of photosynthesis occur in the:
A. Stroma
B. Thylakoid membranes
C. Mitochondria
D. Nucleus
Rationale: The thylakoids contain the chlorophyll needed to capture solar energy.
15. Which molecule acts as the final electron acceptor in the Electron Transport
Chain?
