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 human hepatocytes to
a toxin that selectively disrupts rough endoplasmic
reticulum function. Several hours later, the cells
, demonstrate reduced plasma protein synthesis and
intracellular accumulation of unfinished polypeptides. The
observed findings are most directly explained by failure of
which cellular process?
A. Oxidative phosphorylation within mitochondrial cristae
B. Ribosomal translation and protein folding
C. Lysosomal hydrolysis of damaged proteins
D. Cytoskeletal transport through microtubules
Correct Answer: B
Rationale:
• Clinical Clue: Reduced plasma protein synthesis with
accumulation of unfinished proteins points to defective
rough endoplasmic reticulum activity.
• Mechanism: The rough endoplasmic reticulum contains
ribosomes responsible for synthesis and initial folding of
secretory and membrane proteins.
• Why the Correct Answer Is Right: Hepatocytes synthesize
large amounts of plasma proteins, making them highly
dependent on ribosomal translation and rough ER
processing.
• Why the Other Options Are Wrong:
o A: Oxidative phosphorylation generates ATP but does
not directly synthesize proteins.
, o C: Lysosomes degrade cellular debris rather than
synthesize proteins.
o D: Microtubules transport vesicles but do not perform
translation.
• Exam Trap: Confusing protein transport defects with
protein synthesis defects.
• High-Yield Clinical Correlation: Misfolded protein
accumulation in the ER contributes to ER stress and
apoptosis in many degenerative diseases.
• Memory Anchor: “Rough ER = ribosome-rich protein
factory.”
Q2. A patient with chronic alcohol use develops skeletal
muscle weakness. Muscle biopsy reveals swollen
mitochondria with disrupted cristae. Which cellular
consequence most directly results from this structural
abnormality?
A. Impaired ATP generation
B. Reduced lysosomal enzyme activity
C. Failure of DNA transcription
D. Increased phospholipid synthesis
Correct Answer: A
Rationale:
, • Clinical Clue: Damaged mitochondrial cristae strongly
indicate impaired energy production.
• Mechanism: Cristae contain electron transport chain
proteins required for oxidative phosphorylation and ATP
synthesis.
• Why the Correct Answer Is Right: Disruption of cristae
reduces aerobic ATP production, particularly affecting
high-energy tissues like muscle.
• Why the Other Options Are Wrong:
o B: Lysosomal function is independent of
mitochondrial cristae.
o C: DNA transcription occurs primarily in the nucleus.
o D: Phospholipid synthesis mainly occurs in smooth ER.
• Exam Trap: Associating all intracellular organelle injury
with generalized cell dysfunction rather than the primary
metabolic defect.
• High-Yield Clinical Correlation: Mitochondrial injury is a
major mechanism of irreversible cell injury.
• Memory Anchor: “Cristae create cellular energy.”
Q3. An infant is diagnosed with a congenital disorder
involving defective dynein proteins. Which physiologic
process is most likely to be impaired?
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A researcher exposes cultured human hepatocytes to
a toxin that selectively disrupts rough endoplasmic
reticulum function. Several hours later, the cells
, demonstrate reduced plasma protein synthesis and
intracellular accumulation of unfinished polypeptides. The
observed findings are most directly explained by failure of
which cellular process?
A. Oxidative phosphorylation within mitochondrial cristae
B. Ribosomal translation and protein folding
C. Lysosomal hydrolysis of damaged proteins
D. Cytoskeletal transport through microtubules
Correct Answer: B
Rationale:
• Clinical Clue: Reduced plasma protein synthesis with
accumulation of unfinished proteins points to defective
rough endoplasmic reticulum activity.
• Mechanism: The rough endoplasmic reticulum contains
ribosomes responsible for synthesis and initial folding of
secretory and membrane proteins.
• Why the Correct Answer Is Right: Hepatocytes synthesize
large amounts of plasma proteins, making them highly
dependent on ribosomal translation and rough ER
processing.
• Why the Other Options Are Wrong:
o A: Oxidative phosphorylation generates ATP but does
not directly synthesize proteins.
, o C: Lysosomes degrade cellular debris rather than
synthesize proteins.
o D: Microtubules transport vesicles but do not perform
translation.
• Exam Trap: Confusing protein transport defects with
protein synthesis defects.
• High-Yield Clinical Correlation: Misfolded protein
accumulation in the ER contributes to ER stress and
apoptosis in many degenerative diseases.
• Memory Anchor: “Rough ER = ribosome-rich protein
factory.”
Q2. A patient with chronic alcohol use develops skeletal
muscle weakness. Muscle biopsy reveals swollen
mitochondria with disrupted cristae. Which cellular
consequence most directly results from this structural
abnormality?
A. Impaired ATP generation
B. Reduced lysosomal enzyme activity
C. Failure of DNA transcription
D. Increased phospholipid synthesis
Correct Answer: A
Rationale:
, • Clinical Clue: Damaged mitochondrial cristae strongly
indicate impaired energy production.
• Mechanism: Cristae contain electron transport chain
proteins required for oxidative phosphorylation and ATP
synthesis.
• Why the Correct Answer Is Right: Disruption of cristae
reduces aerobic ATP production, particularly affecting
high-energy tissues like muscle.
• Why the Other Options Are Wrong:
o B: Lysosomal function is independent of
mitochondrial cristae.
o C: DNA transcription occurs primarily in the nucleus.
o D: Phospholipid synthesis mainly occurs in smooth ER.
• Exam Trap: Associating all intracellular organelle injury
with generalized cell dysfunction rather than the primary
metabolic defect.
• High-Yield Clinical Correlation: Mitochondrial injury is a
major mechanism of irreversible cell injury.
• Memory Anchor: “Cristae create cellular energy.”
Q3. An infant is diagnosed with a congenital disorder
involving defective dynein proteins. Which physiologic
process is most likely to be impaired?
