McCance & Huether’s Pathophysiology
The Biologic Basis for Disease in Adults and Children
9th Edition
• Author(s)Julia Rogers
TEST BANK
Chapter 1: Cellular Biology
1. Chapter 1, Cellular Communication and Signal Transduction
A researcher is studying a hormone that binds to a
transmembrane receptor, activating a G-protein which then
stimulates the production of a second messenger inside the
cell. This is an example of which type of cellular signaling?
A. Direct ligand-gated channel signaling
B. Endocrine signaling
C. Signal transduction through receptor-enzyme activation
D. Contact-dependent signaling
Correct Answer: B
Rationale for Correct Answer (B): Endocrine signaling involves
hormones that are released into the bloodstream to act on
target cells at a distance. The described mechanism—a
hormone binding a receptor, activating a G-protein, and
generating an intracellular second messenger—is a classic
example of signal transduction for many endocrine hormones
like epinephrine.
Rationale for Incorrect Answers:
,A: Direct ligand-gated channel signaling involves a ligand
binding to and directly opening an ion channel, without the
need for a G-protein or second messenger.
C: Receptor-enzyme activation (e.g., receptor tyrosine kinases)
involves the receptor itself having enzymatic activity upon
ligand binding, not primarily activating a separate G-protein.
D: Contact-dependent signaling requires cells to be in direct
membrane-to-membrane contact, which is not the case for a
hormone circulating in the bloodstream.
Teaching Point: Endocrine signaling uses circulating hormones
and complex intracellular second messenger systems to elicit a
cellular response.
2. Chapter 1, Structure and Function of Cellular Components
A patient presents with recurrent severe bacterial infections
due to impaired phagocytosis. A genetic defect in which cellular
component is most likely responsible for this clinical
presentation?
A. Rough endoplasmic reticulum
B. Golgi apparatus
C. Lysosomes
D. Peroxisomes
Correct Answer: C
Rationale for Correct Answer (C): Lysosomes are membrane-
bound organelles containing digestive enzymes (hydrolases)
,that are critical for the process of phagocytosis. They fuse with
phagocytic vesicles to degrade ingested material, such as
bacteria.
Rationale for Incorrect Answers:
A: The rough endoplasmic reticulum is involved in protein
synthesis, not the digestive function of phagocytosis.
B: The Golgi apparatus modifies and packages proteins,
including enzymes destined for lysosomes, but is not directly
responsible for the degradative process.
D: Peroxisomes are involved in detoxification and fatty acid
oxidation, not the digestion of phagocytosed pathogens.
Teaching Point: Lysosomes are the primary digestive organelles
of the cell, essential for degrading pathogens engulfed by
phagocytes.
3. Chapter 1, Cellular Metabolism
During a period of prolonged starvation, the body begins to
break down fatty acids to produce ketone bodies for energy.
This metabolic process occurs primarily within which cellular
organelle?
A. Nucleus
B. Mitochondria
C. Lysosomes
D. Cytosol
Correct Answer: B
, Rationale for Correct Answer (B): The mitochondria are the
powerhouse of the cell. Beta-oxidation of fatty acids occurs in
the mitochondrial matrix, and the resulting acetyl-CoA is
further processed in the mitochondria to produce ketone
bodies (ketogenesis).
Rationale for Incorrect Answers:
A: The nucleus contains genetic material and is not involved in
energy production from fatty acids.
C: Lysosomes are involved in catabolism but break down
materials via hydrolysis, not beta-oxidation.
D: While fatty acid activation occurs in the cytosol, the critical
steps of beta-oxidation and ketogenesis are mitochondrial
processes.
Teaching Point: Mitochondria are central to energy production,
including the catabolism of fatty acids into ketone bodies during
starvation.
4. Chapter 1, Membrane Transport: Cellular Intake and Output
Glucose moves from an area of high concentration in the
intestinal lumen into the epithelial cell, against its concentration
gradient, by coupling its transport with the movement of
sodium ions. This process is best described as:
A. Simple diffusion
B. Facilitated diffusion
The Biologic Basis for Disease in Adults and Children
9th Edition
• Author(s)Julia Rogers
TEST BANK
Chapter 1: Cellular Biology
1. Chapter 1, Cellular Communication and Signal Transduction
A researcher is studying a hormone that binds to a
transmembrane receptor, activating a G-protein which then
stimulates the production of a second messenger inside the
cell. This is an example of which type of cellular signaling?
A. Direct ligand-gated channel signaling
B. Endocrine signaling
C. Signal transduction through receptor-enzyme activation
D. Contact-dependent signaling
Correct Answer: B
Rationale for Correct Answer (B): Endocrine signaling involves
hormones that are released into the bloodstream to act on
target cells at a distance. The described mechanism—a
hormone binding a receptor, activating a G-protein, and
generating an intracellular second messenger—is a classic
example of signal transduction for many endocrine hormones
like epinephrine.
Rationale for Incorrect Answers:
,A: Direct ligand-gated channel signaling involves a ligand
binding to and directly opening an ion channel, without the
need for a G-protein or second messenger.
C: Receptor-enzyme activation (e.g., receptor tyrosine kinases)
involves the receptor itself having enzymatic activity upon
ligand binding, not primarily activating a separate G-protein.
D: Contact-dependent signaling requires cells to be in direct
membrane-to-membrane contact, which is not the case for a
hormone circulating in the bloodstream.
Teaching Point: Endocrine signaling uses circulating hormones
and complex intracellular second messenger systems to elicit a
cellular response.
2. Chapter 1, Structure and Function of Cellular Components
A patient presents with recurrent severe bacterial infections
due to impaired phagocytosis. A genetic defect in which cellular
component is most likely responsible for this clinical
presentation?
A. Rough endoplasmic reticulum
B. Golgi apparatus
C. Lysosomes
D. Peroxisomes
Correct Answer: C
Rationale for Correct Answer (C): Lysosomes are membrane-
bound organelles containing digestive enzymes (hydrolases)
,that are critical for the process of phagocytosis. They fuse with
phagocytic vesicles to degrade ingested material, such as
bacteria.
Rationale for Incorrect Answers:
A: The rough endoplasmic reticulum is involved in protein
synthesis, not the digestive function of phagocytosis.
B: The Golgi apparatus modifies and packages proteins,
including enzymes destined for lysosomes, but is not directly
responsible for the degradative process.
D: Peroxisomes are involved in detoxification and fatty acid
oxidation, not the digestion of phagocytosed pathogens.
Teaching Point: Lysosomes are the primary digestive organelles
of the cell, essential for degrading pathogens engulfed by
phagocytes.
3. Chapter 1, Cellular Metabolism
During a period of prolonged starvation, the body begins to
break down fatty acids to produce ketone bodies for energy.
This metabolic process occurs primarily within which cellular
organelle?
A. Nucleus
B. Mitochondria
C. Lysosomes
D. Cytosol
Correct Answer: B
, Rationale for Correct Answer (B): The mitochondria are the
powerhouse of the cell. Beta-oxidation of fatty acids occurs in
the mitochondrial matrix, and the resulting acetyl-CoA is
further processed in the mitochondria to produce ketone
bodies (ketogenesis).
Rationale for Incorrect Answers:
A: The nucleus contains genetic material and is not involved in
energy production from fatty acids.
C: Lysosomes are involved in catabolism but break down
materials via hydrolysis, not beta-oxidation.
D: While fatty acid activation occurs in the cytosol, the critical
steps of beta-oxidation and ketogenesis are mitochondrial
processes.
Teaching Point: Mitochondria are central to energy production,
including the catabolism of fatty acids into ketone bodies during
starvation.
4. Chapter 1, Membrane Transport: Cellular Intake and Output
Glucose moves from an area of high concentration in the
intestinal lumen into the epithelial cell, against its concentration
gradient, by coupling its transport with the movement of
sodium ions. This process is best described as:
A. Simple diffusion
B. Facilitated diffusion
