McCance & Huether’s Pathophysiology
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A 5-year-old child is diagnosed with a mitochondrial
disorder after progressive muscle weakness, exercise
intolerance, and lactic acidosis are noted. Muscle biopsy
, demonstrates structurally abnormal organelles with
disrupted cristae. The patient’s symptoms are most
directly explained by impaired production of which cellular
component?
A. Lysosomal hydrolases
B. Adenosine triphosphate
C. Structural membrane phospholipids
D. Cytosolic ribosomal proteins
Correct Answer: B
Rationale:
• Clinical Clue: Exercise intolerance and lactic acidosis
suggest impaired oxidative phosphorylation.
• Mechanism: Mitochondria generate ATP through aerobic
respiration and electron transport chain activity along the
inner mitochondrial membrane.
• Why the Correct Answer Is Right: Defective cristae impair
oxidative phosphorylation, reducing ATP production in
high-energy tissues such as muscle.
• Why the Other Options Are Wrong:
o A. Lysosomal enzymes are produced mainly in the
rough ER and Golgi apparatus.
o C. Membrane phospholipids are synthesized primarily
in the smooth ER.
, o D. Ribosomal proteins are synthesized in the
cytoplasm and nucleolus.
• Exam Trap: Mitochondrial diseases often present with
neurologic and muscular findings due to high energy
demands.
• High-Yield Clinical Correlation: Cells deprived of oxidative
phosphorylation rely on anaerobic metabolism, increasing
lactate production.
• Memory Anchor: “Cristae create cellular energy.”
Q2. A researcher exposes cultured hepatocytes to a toxin
that disrupts rough endoplasmic reticulum function.
Which cellular process would most likely decline first?
A. Steroid hormone synthesis
B. Oxidative phosphorylation
C. Intracellular protein synthesis
D. Lysosomal degradation
Correct Answer: C
Rationale:
• Clinical Clue: Rough ER dysfunction primarily affects
ribosome-associated activities.
• Mechanism: The rough ER contains membrane-bound
ribosomes responsible for synthesis of secreted and
membrane proteins.
, • Why the Correct Answer Is Right: Hepatocytes depend
heavily on rough ER for plasma protein synthesis.
• Why the Other Options Are Wrong:
o A. Steroid synthesis occurs mainly in smooth ER and
mitochondria.
o B. Oxidative phosphorylation occurs in mitochondria.
o D. Lysosomal degradation occurs within lysosomes.
• Exam Trap: Distinguishing smooth from rough ER functions
is a frequent testing point.
• High-Yield Clinical Correlation: Plasma cells possess
abundant rough ER because of intense immunoglobulin
production.
• Memory Anchor: “Rough ER = ribosomal protein factory.”
Q3. A patient with severe hypercholesterolemia is found
to have defective receptor-mediated endocytosis of low-
density lipoprotein (LDL). Failure of which cellular
structure best accounts for this abnormality?
A. Peroxisomes
B. Clathrin-coated pits
C. Gap junctions
D. Intermediate filaments
Correct Answer: B
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A 5-year-old child is diagnosed with a mitochondrial
disorder after progressive muscle weakness, exercise
intolerance, and lactic acidosis are noted. Muscle biopsy
, demonstrates structurally abnormal organelles with
disrupted cristae. The patient’s symptoms are most
directly explained by impaired production of which cellular
component?
A. Lysosomal hydrolases
B. Adenosine triphosphate
C. Structural membrane phospholipids
D. Cytosolic ribosomal proteins
Correct Answer: B
Rationale:
• Clinical Clue: Exercise intolerance and lactic acidosis
suggest impaired oxidative phosphorylation.
• Mechanism: Mitochondria generate ATP through aerobic
respiration and electron transport chain activity along the
inner mitochondrial membrane.
• Why the Correct Answer Is Right: Defective cristae impair
oxidative phosphorylation, reducing ATP production in
high-energy tissues such as muscle.
• Why the Other Options Are Wrong:
o A. Lysosomal enzymes are produced mainly in the
rough ER and Golgi apparatus.
o C. Membrane phospholipids are synthesized primarily
in the smooth ER.
, o D. Ribosomal proteins are synthesized in the
cytoplasm and nucleolus.
• Exam Trap: Mitochondrial diseases often present with
neurologic and muscular findings due to high energy
demands.
• High-Yield Clinical Correlation: Cells deprived of oxidative
phosphorylation rely on anaerobic metabolism, increasing
lactate production.
• Memory Anchor: “Cristae create cellular energy.”
Q2. A researcher exposes cultured hepatocytes to a toxin
that disrupts rough endoplasmic reticulum function.
Which cellular process would most likely decline first?
A. Steroid hormone synthesis
B. Oxidative phosphorylation
C. Intracellular protein synthesis
D. Lysosomal degradation
Correct Answer: C
Rationale:
• Clinical Clue: Rough ER dysfunction primarily affects
ribosome-associated activities.
• Mechanism: The rough ER contains membrane-bound
ribosomes responsible for synthesis of secreted and
membrane proteins.
, • Why the Correct Answer Is Right: Hepatocytes depend
heavily on rough ER for plasma protein synthesis.
• Why the Other Options Are Wrong:
o A. Steroid synthesis occurs mainly in smooth ER and
mitochondria.
o B. Oxidative phosphorylation occurs in mitochondria.
o D. Lysosomal degradation occurs within lysosomes.
• Exam Trap: Distinguishing smooth from rough ER functions
is a frequent testing point.
• High-Yield Clinical Correlation: Plasma cells possess
abundant rough ER because of intense immunoglobulin
production.
• Memory Anchor: “Rough ER = ribosomal protein factory.”
Q3. A patient with severe hypercholesterolemia is found
to have defective receptor-mediated endocytosis of low-
density lipoprotein (LDL). Failure of which cellular
structure best accounts for this abnormality?
A. Peroxisomes
B. Clathrin-coated pits
C. Gap junctions
D. Intermediate filaments
Correct Answer: B
