Biology 198 - Cell Biology
Exam 3 Review Questions and Answers
Cell Structure, Function, and Processes
1. Cell Membrane Structure and Transport
Question 1:
The fluid mosaic model describes the cell membrane as having which key
characteristics?
A) A rigid, impermeable barrier
B) A fluid phospholipid bilayer with embedded proteins
C) A single layer of proteins
D) A crystalline structure
Answer: B) A fluid phospholipid bilayer with embedded proteins
The fluid mosaic model describes membranes as dynamic structures with
phospholipids that can move laterally and proteins that float within the lipid bilayer.
Question 2:
Which transport mechanism requires energy (ATP) to move substances across the
membrane?
A) Simple diffusion
B) Facilitated diffusion
C) Active transport
D) Osmosis
Answer: C) Active transport
Active transport moves substances against their concentration gradient, requiring
energy input in the form of ATP.
Question 3:
The sodium-potassium pump is an example of:
A) Passive transport
B) Primary active transport
C) Facilitated diffusion
D) Simple diffusion
Answer: B) Primary active transport
The Na+/K+ pump directly uses ATP to transport 3 Na+ out and 2 K+ in, against
their concentration gradients.
2. Cellular Respiration
Question 4:
The overall equation for cellular respiration is:
A) C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
B) 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂
, C) ADP + Pi → ATP
D) ATP → ADP + Pi
Answer: A) C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
Cellular respiration breaks down glucose using oxygen to produce carbon dioxide,
water, and ATP energy.
Question 5:
Which stage of cellular respiration produces the most ATP?
A) Glycolysis
B) Citric acid cycle (Krebs cycle)
C) Electron transport chain
D) Fermentation
Answer: C) Electron transport chain
The electron transport chain produces approximately 32-34 ATP molecules through
oxidative phosphorylation, far more than glycolysis (2 ATP) or the citric acid cycle (2
ATP).
Question 6:
Where does glycolysis occur in the cell?
A) Mitochondrial matrix
B) Cytoplasm
C) Nucleus
D) Endoplasmic reticulum
Answer: B) Cytoplasm
Glycolysis occurs in the cytoplasm and does not require organelles, making it
possible in both prokaryotic and eukaryotic cells.
3. Photosynthesis
Question 7:
The light-dependent reactions of photosynthesis occur in the:
A) Stroma
B) Thylakoid membranes
C) Cytoplasm
D) Nucleus
Answer: B) Thylakoid membranes
The light-dependent reactions occur in the thylakoid membranes where chlorophyll
captures light energy and converts it to chemical energy (ATP and NADPH).
Question 8:
The Calvin cycle (light-independent reactions) produces:
A) Oxygen
B) ATP
C) Glucose (G3P)
D) Water
Exam 3 Review Questions and Answers
Cell Structure, Function, and Processes
1. Cell Membrane Structure and Transport
Question 1:
The fluid mosaic model describes the cell membrane as having which key
characteristics?
A) A rigid, impermeable barrier
B) A fluid phospholipid bilayer with embedded proteins
C) A single layer of proteins
D) A crystalline structure
Answer: B) A fluid phospholipid bilayer with embedded proteins
The fluid mosaic model describes membranes as dynamic structures with
phospholipids that can move laterally and proteins that float within the lipid bilayer.
Question 2:
Which transport mechanism requires energy (ATP) to move substances across the
membrane?
A) Simple diffusion
B) Facilitated diffusion
C) Active transport
D) Osmosis
Answer: C) Active transport
Active transport moves substances against their concentration gradient, requiring
energy input in the form of ATP.
Question 3:
The sodium-potassium pump is an example of:
A) Passive transport
B) Primary active transport
C) Facilitated diffusion
D) Simple diffusion
Answer: B) Primary active transport
The Na+/K+ pump directly uses ATP to transport 3 Na+ out and 2 K+ in, against
their concentration gradients.
2. Cellular Respiration
Question 4:
The overall equation for cellular respiration is:
A) C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
B) 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂
, C) ADP + Pi → ATP
D) ATP → ADP + Pi
Answer: A) C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
Cellular respiration breaks down glucose using oxygen to produce carbon dioxide,
water, and ATP energy.
Question 5:
Which stage of cellular respiration produces the most ATP?
A) Glycolysis
B) Citric acid cycle (Krebs cycle)
C) Electron transport chain
D) Fermentation
Answer: C) Electron transport chain
The electron transport chain produces approximately 32-34 ATP molecules through
oxidative phosphorylation, far more than glycolysis (2 ATP) or the citric acid cycle (2
ATP).
Question 6:
Where does glycolysis occur in the cell?
A) Mitochondrial matrix
B) Cytoplasm
C) Nucleus
D) Endoplasmic reticulum
Answer: B) Cytoplasm
Glycolysis occurs in the cytoplasm and does not require organelles, making it
possible in both prokaryotic and eukaryotic cells.
3. Photosynthesis
Question 7:
The light-dependent reactions of photosynthesis occur in the:
A) Stroma
B) Thylakoid membranes
C) Cytoplasm
D) Nucleus
Answer: B) Thylakoid membranes
The light-dependent reactions occur in the thylakoid membranes where chlorophyll
captures light energy and converts it to chemical energy (ATP and NADPH).
Question 8:
The Calvin cycle (light-independent reactions) produces:
A) Oxygen
B) ATP
C) Glucose (G3P)
D) Water
