NU 545 Pathophysiology Complete Exam Study Guide
Units 1–7 | University of South Alabama | 2026/2027
Academic Year
Verified Questions with Correct Answers & Detailed Rationales
UNIT 1: CELLULAR FOUNDATIONS (Questions 1–25)
Question 1. Which cellular function is demonstrated by intestinal epithelial cells
absorbing nutrients from digested food?
A. Conductivity
B. Metabolic absorption
C. Secretion
D. Communication
Correct Answer: B
Rationale: Metabolic absorption is the ability of cells to take in and use nutrients and
other substances from their surroundings. Intestinal epithelial cells are specialized to
absorb fluids and nutrients, making them a classic example of this cellular function .
Conductivity refers to the transmission of electrical signals, secretion is the release of
substances like hormones, and communication involves signaling between cells—none
of which describe nutrient uptake from the gastrointestinal tract.
Question 2. A graduate nursing student is studying cellular organelles. Which organelle
contains enzymes that use oxygen to remove hydrogen atoms in oxidative reactions,
producing hydrogen peroxide?
A. Lysosomes
B. Mitochondria
,C. Peroxisomes
D. Golgi apparatus
Correct Answer: C
Rationale: Peroxisomes contain enzymes that use oxygen to remove hydrogen atoms in
oxidative reactions, producing hydrogen peroxide (H₂O₂) as a byproduct . Lysosomes
contain digestive enzymes for cellular autodigestion, mitochondria are the site of ATP
production via oxidative phosphorylation, and the Golgi apparatus is responsible for
protein modification and packaging.
Question 3. During cellular injury, which organelle releases enzymes capable of causing
cellular autodigestion?
A. Peroxisomes
B. Ribosomes
C. Lysosomes
D. Endoplasmic reticulum
Correct Answer: C
Rationale: Lysosomes are sac-like structures containing more than 40 digestive
enzymes called hydrolases. Disruption of the lysosomal membrane by cellular injury
leads to the release of these enzymes, causing cellular self-digestion (autodigestion) .
Lysosomes are crucial for normal digestion of cellular nutrients and removal of
intercellular debris.
Question 4. The nucleus is considered the "control center" of the cell. Which function is
primarily associated with the nucleus?
A. Production of ATP
B. Protein folding and packaging
C. Cell division and control of genetic information
D. Synthesis of lysosomal enzymes
Correct Answer: C
,Rationale: The nucleus contains most cellular DNA and associated histones and is
primarily responsible for cell division, control of genetic information, and DNA
replication and repair . ATP production occurs in mitochondria, protein packaging in the
Golgi complex, and lysosomal enzymes are synthesized in the rough endoplasmic
reticulum.
Question 5. Which major chemical component is NOT a primary component of the
plasma membrane?
A. Phospholipids
B. Proteins
C. Carbohydrates
D. Nucleic acids
Correct Answer: D
Rationale: Nucleic acids (DNA and RNA) are nuclear or cytoplasmic components and
are not primary structural components of the plasma membrane . The plasma
membrane is a lipid bilayer primarily composed of phospholipids, interspersed with
proteins and membrane-associated carbohydrates (as glycoproteins and glycolipids).
Cholesterol is also present to maintain membrane fluidity.
Question 6. Which property of phospholipids is essential for the self-assembly of the
cell membrane into a lipid bilayer?
A. Nonpolar, completely hydrophobic structure
B. Amphipathic nature with hydrophilic and hydrophobic regions
C. Ability to bind directly to DNA
D. High-energy phosphate bonds for ATP synthesis
Correct Answer: B
Rationale: Phospholipids are amphipathic, meaning they have polar, hydrophilic (water-
loving) heads and nonpolar, hydrophobic (water-fearing) tails. This dual property drives
spontaneous self-assembly into a bilayer, creating a barrier to water-soluble substances
, while allowing membrane integrity . The other options describe different molecular
properties unrelated to bilayer formation.
Question 7. What is the primary mechanism by which potassium ions diffuse down their
concentration gradient across the plasma membrane?
A. Active transport via the Na⁺/K⁺-ATPase pump
B. Movement through protein channels
C. Endocytosis and exocytosis
D. Diffusion through the lipid bilayer
Correct Answer: B
Rationale: Potassium ions diffuse down their concentration gradient through specific
protein channels in the plasma membrane. These channels allow K⁺ to move from areas
of higher concentration to areas of lower concentration . The Na⁺/K⁺-ATPase pump
works against the concentration gradient using ATP, and the lipid bilayer is
impermeable to charged ions.
Question 8. How does the glycocalyx protect cells from injury?
A. By maintaining membrane fluidity
B. By forming a protective coating that protects from mechanical damage
C. By facilitating active transport of nutrients
D. By producing ATP during cellular stress
Correct Answer: B
Rationale: The carbohydrates on the outside of the plasma membrane form a coating
called the glycocalyx that protects cells from mechanical damage . The glycocalyx also
plays roles in cell recognition and adhesion. Membrane fluidity is maintained by
cholesterol, active transport is performed by membrane proteins, and ATP production
occurs in mitochondria.
Units 1–7 | University of South Alabama | 2026/2027
Academic Year
Verified Questions with Correct Answers & Detailed Rationales
UNIT 1: CELLULAR FOUNDATIONS (Questions 1–25)
Question 1. Which cellular function is demonstrated by intestinal epithelial cells
absorbing nutrients from digested food?
A. Conductivity
B. Metabolic absorption
C. Secretion
D. Communication
Correct Answer: B
Rationale: Metabolic absorption is the ability of cells to take in and use nutrients and
other substances from their surroundings. Intestinal epithelial cells are specialized to
absorb fluids and nutrients, making them a classic example of this cellular function .
Conductivity refers to the transmission of electrical signals, secretion is the release of
substances like hormones, and communication involves signaling between cells—none
of which describe nutrient uptake from the gastrointestinal tract.
Question 2. A graduate nursing student is studying cellular organelles. Which organelle
contains enzymes that use oxygen to remove hydrogen atoms in oxidative reactions,
producing hydrogen peroxide?
A. Lysosomes
B. Mitochondria
,C. Peroxisomes
D. Golgi apparatus
Correct Answer: C
Rationale: Peroxisomes contain enzymes that use oxygen to remove hydrogen atoms in
oxidative reactions, producing hydrogen peroxide (H₂O₂) as a byproduct . Lysosomes
contain digestive enzymes for cellular autodigestion, mitochondria are the site of ATP
production via oxidative phosphorylation, and the Golgi apparatus is responsible for
protein modification and packaging.
Question 3. During cellular injury, which organelle releases enzymes capable of causing
cellular autodigestion?
A. Peroxisomes
B. Ribosomes
C. Lysosomes
D. Endoplasmic reticulum
Correct Answer: C
Rationale: Lysosomes are sac-like structures containing more than 40 digestive
enzymes called hydrolases. Disruption of the lysosomal membrane by cellular injury
leads to the release of these enzymes, causing cellular self-digestion (autodigestion) .
Lysosomes are crucial for normal digestion of cellular nutrients and removal of
intercellular debris.
Question 4. The nucleus is considered the "control center" of the cell. Which function is
primarily associated with the nucleus?
A. Production of ATP
B. Protein folding and packaging
C. Cell division and control of genetic information
D. Synthesis of lysosomal enzymes
Correct Answer: C
,Rationale: The nucleus contains most cellular DNA and associated histones and is
primarily responsible for cell division, control of genetic information, and DNA
replication and repair . ATP production occurs in mitochondria, protein packaging in the
Golgi complex, and lysosomal enzymes are synthesized in the rough endoplasmic
reticulum.
Question 5. Which major chemical component is NOT a primary component of the
plasma membrane?
A. Phospholipids
B. Proteins
C. Carbohydrates
D. Nucleic acids
Correct Answer: D
Rationale: Nucleic acids (DNA and RNA) are nuclear or cytoplasmic components and
are not primary structural components of the plasma membrane . The plasma
membrane is a lipid bilayer primarily composed of phospholipids, interspersed with
proteins and membrane-associated carbohydrates (as glycoproteins and glycolipids).
Cholesterol is also present to maintain membrane fluidity.
Question 6. Which property of phospholipids is essential for the self-assembly of the
cell membrane into a lipid bilayer?
A. Nonpolar, completely hydrophobic structure
B. Amphipathic nature with hydrophilic and hydrophobic regions
C. Ability to bind directly to DNA
D. High-energy phosphate bonds for ATP synthesis
Correct Answer: B
Rationale: Phospholipids are amphipathic, meaning they have polar, hydrophilic (water-
loving) heads and nonpolar, hydrophobic (water-fearing) tails. This dual property drives
spontaneous self-assembly into a bilayer, creating a barrier to water-soluble substances
, while allowing membrane integrity . The other options describe different molecular
properties unrelated to bilayer formation.
Question 7. What is the primary mechanism by which potassium ions diffuse down their
concentration gradient across the plasma membrane?
A. Active transport via the Na⁺/K⁺-ATPase pump
B. Movement through protein channels
C. Endocytosis and exocytosis
D. Diffusion through the lipid bilayer
Correct Answer: B
Rationale: Potassium ions diffuse down their concentration gradient through specific
protein channels in the plasma membrane. These channels allow K⁺ to move from areas
of higher concentration to areas of lower concentration . The Na⁺/K⁺-ATPase pump
works against the concentration gradient using ATP, and the lipid bilayer is
impermeable to charged ions.
Question 8. How does the glycocalyx protect cells from injury?
A. By maintaining membrane fluidity
B. By forming a protective coating that protects from mechanical damage
C. By facilitating active transport of nutrients
D. By producing ATP during cellular stress
Correct Answer: B
Rationale: The carbohydrates on the outside of the plasma membrane form a coating
called the glycocalyx that protects cells from mechanical damage . The glycocalyx also
plays roles in cell recognition and adhesion. Membrane fluidity is maintained by
cholesterol, active transport is performed by membrane proteins, and ATP production
occurs in mitochondria.
