Robbins Basic Pathology
10th Edition
Author(s)Vinay Kumar; MBBS; MD;
FRCPath; Abul K. Abbas; MBBS and
Jon C. Aster; MD; PhD
Print ISBN: 9780323353175
,Question 1
A patient develops a severe reduction in cellular ATP production after
prolonged interruption of blood flow to a tissue. Which cellular process
is most directly impaired by ATP depletion?
A. DNA replication
B. Maintenance of ionic gradients across the plasma membrane
C. Collagen synthesis in the extracellular matrix
D. Activation of growth factor receptors
,Correct Answer: B. Maintenance of ionic gradients across the plasma
membrane
Rationale: ATP is required to power membrane ion pumps, particularly
the Na⁺/K⁺-ATPase. When ATP falls, these pumps fail, causing
intracellular sodium and water accumulation and cellular swelling. DNA
replication, collagen synthesis, and receptor activation may also be
affected by cellular injury, but failure of ionic homeostasis is an early
and direct consequence of ATP depletion.
Question 2
Which statement best describes the primary function of the genome in
a healthy cell?
A. It directly produces ATP for cellular metabolism
B. It stores hereditary information that directs cellular structure and
function
C. It packages proteins into secretory vesicles
D. It removes damaged organelles from the cytoplasm
Correct Answer: B. It stores hereditary information that directs cellular
structure and function
Rationale: The genome contains the genetic information required for
synthesis of proteins and regulation of cellular activities. It does not
directly generate ATP, package proteins, or degrade organelles. Those
functions are carried out by specialized cellular structures and
biochemical systems.
Question 3
, A hepatocyte synthesizes a secreted plasma protein. Which sequence
correctly describes the major pathway followed by the newly
synthesized protein?
A. Nucleus → mitochondrion → lysosome → plasma membrane
B. Ribosome on rough endoplasmic reticulum → Golgi apparatus →
secretory vesicle → plasma membrane
C. Smooth endoplasmic reticulum → nucleus → Golgi apparatus →
lysosome
D. Golgi apparatus → ribosome → secretory vesicle → plasma
membrane
Correct Answer: B. Ribosome on rough endoplasmic reticulum → Golgi
apparatus → secretory vesicle → plasma membrane
Rationale: Proteins destined for secretion are synthesized on ribosomes
attached to the rough endoplasmic reticulum. They are transported to
the Golgi apparatus for modification and sorting, then packaged into
secretory vesicles that fuse with the plasma membrane. The other
sequences incorrectly place organelles in the secretory pathway.
Question 4
A toxin selectively inhibits mitochondrial oxidative phosphorylation.
Which immediate cellular consequence is most likely?
A. Increased ATP generation
B. Reduced ATP availability with impaired energy-dependent functions
C. Increased synthesis of extracellular matrix proteins
D. Increased DNA replication
Correct Answer: B. Reduced ATP availability with impaired energy-
dependent functions
10th Edition
Author(s)Vinay Kumar; MBBS; MD;
FRCPath; Abul K. Abbas; MBBS and
Jon C. Aster; MD; PhD
Print ISBN: 9780323353175
,Question 1
A patient develops a severe reduction in cellular ATP production after
prolonged interruption of blood flow to a tissue. Which cellular process
is most directly impaired by ATP depletion?
A. DNA replication
B. Maintenance of ionic gradients across the plasma membrane
C. Collagen synthesis in the extracellular matrix
D. Activation of growth factor receptors
,Correct Answer: B. Maintenance of ionic gradients across the plasma
membrane
Rationale: ATP is required to power membrane ion pumps, particularly
the Na⁺/K⁺-ATPase. When ATP falls, these pumps fail, causing
intracellular sodium and water accumulation and cellular swelling. DNA
replication, collagen synthesis, and receptor activation may also be
affected by cellular injury, but failure of ionic homeostasis is an early
and direct consequence of ATP depletion.
Question 2
Which statement best describes the primary function of the genome in
a healthy cell?
A. It directly produces ATP for cellular metabolism
B. It stores hereditary information that directs cellular structure and
function
C. It packages proteins into secretory vesicles
D. It removes damaged organelles from the cytoplasm
Correct Answer: B. It stores hereditary information that directs cellular
structure and function
Rationale: The genome contains the genetic information required for
synthesis of proteins and regulation of cellular activities. It does not
directly generate ATP, package proteins, or degrade organelles. Those
functions are carried out by specialized cellular structures and
biochemical systems.
Question 3
, A hepatocyte synthesizes a secreted plasma protein. Which sequence
correctly describes the major pathway followed by the newly
synthesized protein?
A. Nucleus → mitochondrion → lysosome → plasma membrane
B. Ribosome on rough endoplasmic reticulum → Golgi apparatus →
secretory vesicle → plasma membrane
C. Smooth endoplasmic reticulum → nucleus → Golgi apparatus →
lysosome
D. Golgi apparatus → ribosome → secretory vesicle → plasma
membrane
Correct Answer: B. Ribosome on rough endoplasmic reticulum → Golgi
apparatus → secretory vesicle → plasma membrane
Rationale: Proteins destined for secretion are synthesized on ribosomes
attached to the rough endoplasmic reticulum. They are transported to
the Golgi apparatus for modification and sorting, then packaged into
secretory vesicles that fuse with the plasma membrane. The other
sequences incorrectly place organelles in the secretory pathway.
Question 4
A toxin selectively inhibits mitochondrial oxidative phosphorylation.
Which immediate cellular consequence is most likely?
A. Increased ATP generation
B. Reduced ATP availability with impaired energy-dependent functions
C. Increased synthesis of extracellular matrix proteins
D. Increased DNA replication
Correct Answer: B. Reduced ATP availability with impaired energy-
dependent functions
