PCB3023C Exam 2: Cell Biology 2026 FGCU
1. Which component of the plasma membrane is primarily responsible for its
fluid nature?
A. Integral proteins
B. Glycoproteins
C. Phospholipids
D. Peripheral proteins
Answer: C
Rationale: The lipid bilayer, composed of phospholipids, provides the fundamental fluid
structure of the membrane.
2. Which of the following molecules can most easily pass through the lipid
bilayer without the help of a transport protein?
A. Glucose
B. Sodium ions (Na+)
C. Amino acids
D. Oxygen (O2)
Answer: D
Rationale: Small, nonpolar molecules like oxygen and carbon dioxide can diffuse directly
through the hydrophobic core of the lipid bilayer.
,3. What is the primary function of the Sodium-Potassium pump (Na+/K+
ATPase)?
A. To transport Na+ into the cell and K+ out of the cell
B. To transport both Na+ and K+ out of the cell
C. To transport glucose into the cell
D. To transport Na+ out of the cell and K+ into the cell
Answer: D
Rationale: The Na+/K+ pump uses ATP to move 3 sodium ions out and 2 potassium ions in
against their concentration gradients.
4. In which part of the cell does glycolysis occur?
A. Mitochondrial matrix
B. Intermembrane space
C. Endoplasmic reticulum
D. Cytosol
Answer: D
Rationale: Glycolysis is the first stage of cellular respiration and takes place in the cytosol
of the cell.
5. What is the net gain of ATP molecules produced from one molecule of glucose
during glycolysis?
A. 32 ATP
B. 4 ATP
C. 2 ATP
D. 36 ATP
Answer: C
Rationale: While 4 ATP are produced, 2 ATP are consumed in the investment phase,
resulting in a net gain of 2 ATP.
, 6. Which molecule acts as the final electron acceptor in the mitochondrial
electron transport chain?
A. NAD+
B. Oxygen (O2)
C. FAD
D. Water (H2O)
Answer: B
Rationale: Oxygen accepts the final electrons and combines with protons to form water.
7. During chemiosmosis, what drives the synthesis of ATP by ATP synthase?
A. The movement of electrons through the ETC
B. The reduction of NAD+
C. The proton (H+) gradient across the inner membrane
D. The oxidation of glucose
Answer: C
Rationale: The flow of protons down their electrochemical gradient through ATP synthase
provides the energy for ATP synthesis.
8. Where does the Citric Acid Cycle (Krebs Cycle) take place?
A. Cytosol
B. Mitochondrial cristae
C. Mitochondrial matrix
D. Thylakoid lumen
Answer: C
Rationale: The Citric Acid Cycle occurs within the matrix of the mitochondria.
1. Which component of the plasma membrane is primarily responsible for its
fluid nature?
A. Integral proteins
B. Glycoproteins
C. Phospholipids
D. Peripheral proteins
Answer: C
Rationale: The lipid bilayer, composed of phospholipids, provides the fundamental fluid
structure of the membrane.
2. Which of the following molecules can most easily pass through the lipid
bilayer without the help of a transport protein?
A. Glucose
B. Sodium ions (Na+)
C. Amino acids
D. Oxygen (O2)
Answer: D
Rationale: Small, nonpolar molecules like oxygen and carbon dioxide can diffuse directly
through the hydrophobic core of the lipid bilayer.
,3. What is the primary function of the Sodium-Potassium pump (Na+/K+
ATPase)?
A. To transport Na+ into the cell and K+ out of the cell
B. To transport both Na+ and K+ out of the cell
C. To transport glucose into the cell
D. To transport Na+ out of the cell and K+ into the cell
Answer: D
Rationale: The Na+/K+ pump uses ATP to move 3 sodium ions out and 2 potassium ions in
against their concentration gradients.
4. In which part of the cell does glycolysis occur?
A. Mitochondrial matrix
B. Intermembrane space
C. Endoplasmic reticulum
D. Cytosol
Answer: D
Rationale: Glycolysis is the first stage of cellular respiration and takes place in the cytosol
of the cell.
5. What is the net gain of ATP molecules produced from one molecule of glucose
during glycolysis?
A. 32 ATP
B. 4 ATP
C. 2 ATP
D. 36 ATP
Answer: C
Rationale: While 4 ATP are produced, 2 ATP are consumed in the investment phase,
resulting in a net gain of 2 ATP.
, 6. Which molecule acts as the final electron acceptor in the mitochondrial
electron transport chain?
A. NAD+
B. Oxygen (O2)
C. FAD
D. Water (H2O)
Answer: B
Rationale: Oxygen accepts the final electrons and combines with protons to form water.
7. During chemiosmosis, what drives the synthesis of ATP by ATP synthase?
A. The movement of electrons through the ETC
B. The reduction of NAD+
C. The proton (H+) gradient across the inner membrane
D. The oxidation of glucose
Answer: C
Rationale: The flow of protons down their electrochemical gradient through ATP synthase
provides the energy for ATP synthesis.
8. Where does the Citric Acid Cycle (Krebs Cycle) take place?
A. Cytosol
B. Mitochondrial cristae
C. Mitochondrial matrix
D. Thylakoid lumen
Answer: C
Rationale: The Citric Acid Cycle occurs within the matrix of the mitochondria.
