McCance & Huether’s Pathophysiology
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A researcher exposes cultured hepatocytes to a toxin that
selectively disrupts rough endoplasmic reticulum function.
Within hours, the cells demonstrate impaired plasma protein
synthesis and intracellular protein accumulation. The observed
changes are most directly explained by failure of which cellular
process?
A. Oxidative phosphorylation
B. Post-translational protein folding and transport
,C. Lysosomal degradation of damaged organelles
D. DNA replication during S phase
Correct Answer: B
Rationale:
• Clinical Clue: Impaired plasma protein synthesis with
intracellular accumulation suggests defective protein
processing.
• Mechanism: Rough endoplasmic reticulum (RER)
synthesizes and folds membrane-bound and secreted
proteins before Golgi transport.
• Why the Correct Answer Is Right: Disruption of RER
prevents proper folding and trafficking of newly
synthesized proteins, causing accumulation.
• Why the Other Options Are Wrong:
o A. Oxidative phosphorylation occurs in mitochondria.
o C. Lysosomal degradation is mediated primarily by
lysosomes and autophagy pathways.
o D. DNA replication occurs in the nucleus during S
phase.
• Exam Trap: Confusing protein synthesis with energy
production.
, • High-Yield Clinical Correlation: Misfolded protein
accumulation contributes to diseases such as alpha-1
antitrypsin deficiency.
• Memory Anchor: “RER = Ribosomes Export proteins
Rapidly.”
Q2. A patient with recurrent bacterial infections is found to
have defective neutrophil phagolysosome formation. Which
intracellular structure most directly contributes hydrolytic
enzymes necessary for microbial degradation?
A. Peroxisomes
B. Golgi apparatus
C. Lysosomes
D. Smooth endoplasmic reticulum
Correct Answer: C
Rationale:
• Clinical Clue: Defective intracellular killing after
phagocytosis implicates lysosomal dysfunction.
• Mechanism: Lysosomes contain acid hydrolases that
degrade engulfed pathogens after fusion with
phagosomes.
• Why the Correct Answer Is Right: Lysosomes provide
digestive enzymes necessary for phagolysosomal activity.
• Why the Other Options Are Wrong:
, o A. Peroxisomes mainly metabolize fatty acids and
detoxify hydrogen peroxide.
o B. Golgi apparatus modifies and packages proteins.
o D. Smooth ER synthesizes lipids and detoxifies drugs.
• Exam Trap: Confusing lysosomal enzymes with
peroxisomal oxidative enzymes.
• High-Yield Clinical Correlation: Lysosomal dysfunction
underlies disorders such as Chediak-Higashi syndrome.
• Memory Anchor: “Lysosomes lyse.”
Q3. A mutation prevents phosphorylation of intracellular
signaling proteins after activation of a membrane receptor.
Despite normal ligand binding, downstream gene transcription
is markedly reduced. Which process is primarily impaired?
A. Passive diffusion
B. Signal transduction
C. Endocytosis
D. Cytoskeletal polymerization
Correct Answer: B
Rationale:
• Clinical Clue: Normal receptor binding but failed
intracellular response indicates defective signaling
cascade.
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A researcher exposes cultured hepatocytes to a toxin that
selectively disrupts rough endoplasmic reticulum function.
Within hours, the cells demonstrate impaired plasma protein
synthesis and intracellular protein accumulation. The observed
changes are most directly explained by failure of which cellular
process?
A. Oxidative phosphorylation
B. Post-translational protein folding and transport
,C. Lysosomal degradation of damaged organelles
D. DNA replication during S phase
Correct Answer: B
Rationale:
• Clinical Clue: Impaired plasma protein synthesis with
intracellular accumulation suggests defective protein
processing.
• Mechanism: Rough endoplasmic reticulum (RER)
synthesizes and folds membrane-bound and secreted
proteins before Golgi transport.
• Why the Correct Answer Is Right: Disruption of RER
prevents proper folding and trafficking of newly
synthesized proteins, causing accumulation.
• Why the Other Options Are Wrong:
o A. Oxidative phosphorylation occurs in mitochondria.
o C. Lysosomal degradation is mediated primarily by
lysosomes and autophagy pathways.
o D. DNA replication occurs in the nucleus during S
phase.
• Exam Trap: Confusing protein synthesis with energy
production.
, • High-Yield Clinical Correlation: Misfolded protein
accumulation contributes to diseases such as alpha-1
antitrypsin deficiency.
• Memory Anchor: “RER = Ribosomes Export proteins
Rapidly.”
Q2. A patient with recurrent bacterial infections is found to
have defective neutrophil phagolysosome formation. Which
intracellular structure most directly contributes hydrolytic
enzymes necessary for microbial degradation?
A. Peroxisomes
B. Golgi apparatus
C. Lysosomes
D. Smooth endoplasmic reticulum
Correct Answer: C
Rationale:
• Clinical Clue: Defective intracellular killing after
phagocytosis implicates lysosomal dysfunction.
• Mechanism: Lysosomes contain acid hydrolases that
degrade engulfed pathogens after fusion with
phagosomes.
• Why the Correct Answer Is Right: Lysosomes provide
digestive enzymes necessary for phagolysosomal activity.
• Why the Other Options Are Wrong:
, o A. Peroxisomes mainly metabolize fatty acids and
detoxify hydrogen peroxide.
o B. Golgi apparatus modifies and packages proteins.
o D. Smooth ER synthesizes lipids and detoxifies drugs.
• Exam Trap: Confusing lysosomal enzymes with
peroxisomal oxidative enzymes.
• High-Yield Clinical Correlation: Lysosomal dysfunction
underlies disorders such as Chediak-Higashi syndrome.
• Memory Anchor: “Lysosomes lyse.”
Q3. A mutation prevents phosphorylation of intracellular
signaling proteins after activation of a membrane receptor.
Despite normal ligand binding, downstream gene transcription
is markedly reduced. Which process is primarily impaired?
A. Passive diffusion
B. Signal transduction
C. Endocytosis
D. Cytoskeletal polymerization
Correct Answer: B
Rationale:
• Clinical Clue: Normal receptor binding but failed
intracellular response indicates defective signaling
cascade.
