,NU189/NU 189 Exam 2 | Medical-Surgical Nursing II |
Galen College | Q & A | 2026/2027 Edition (PDF)
1. Which of the following best describes the process by which a cell engulfs a large particle into a
vacuole?
A) Pinocytosis
B) Phagocytosis
C) Receptor-mediated endocytosis
D) Exocytosis
Correct Answer: Phagocytosis
Expert Rationale: Phagocytosis, or "cellular eating," is the process by which a cell engulfs a large particle
into a vacuole. Pinocytosis involves "cellular drinking" of extracellular fluid. Receptor-mediated
endocytosis is more specific, triggered by ligand binding, while exocytosis releases substances from the
cell.
2. What is the primary function of the sodium-potassium pump in active transport?
A) To move glucose and sodium simultaneously across the membrane
B) To move sodium and potassium ions across the cell membrane using ATP
C) To engulf extracellular fluid into tiny vesicles
D) To release cellular contents through vesicle fusion
Correct Answer: To move sodium and potassium ions across the cell membrane using ATP
Expert Rationale: The sodium-potassium pump moves sodium and potassium ions across the cell
membrane, involving the hydrolysis of ATP to produce the necessary energy. This maintains the resting
membrane potential. Co-transport moves two substances simultaneously without ATP, while
endocytosis and exocytosis are distinct processes.
3. In receptor-mediated endocytosis, what triggers the formation of a vesicle?
,A) The engulfment of a large particle
B) The "gulping" of extracellular fluid
C) The binding of a ligand to a specific receptor site
D) The fusion of a transport vesicle with the membrane
Correct Answer: The binding of a ligand to a specific receptor site
Expert Rationale: In receptor-mediated endocytosis, the binding of ligands (any molecule that binds
specifically to a receptor site) to receptors triggers vesicle formation. This process is more specific than
phagocytosis or pinocytosis. Exocytosis involves vesicle fusion with the membrane to release contents.
4. What does it mean for a carrier protein to be saturated?
A) The carrier protein has no binding sites available
B) All the binding sites on the carrier protein are occupied
C) The carrier protein is unable to transport any substances
D) The carrier protein has been denatured
Correct Answer: All the binding sites on the carrier protein are occupied
Expert Rationale: Saturated carrier proteins mean all the binding that the protein can do is used,
meaning all sides are bound up. This limits the rate of transport across the membrane. This concept is
important for understanding drug transport and absorption.
5. A researcher is studying the movement of substances across a cell membrane. Which type of
transport moves two substances simultaneously across a membrane by one protein complex without
using ATP?
A) Sodium-potassium pump
B) Primary active transport
C) Co-transport mechanism
D) Endocytosis
, Correct Answer: Co-transport mechanism
Expert Rationale: The co-transport mechanism moves two substances simultaneously across a
membrane by one protein or complex protein with no ATP activity. The sodium-potassium pump uses
ATP, and endocytosis involves vesicle formation.
6. Which of the following nitrogenous bases is classified as a purine?
A) Cytosine
B) Thymine
C) Adenine
D) Uracil
Correct Answer: Adenine
Expert Rationale: Purines are larger, consisting of a six-membered ring fused to a five-membered ring,
and include adenine (A) and guanine (G). Pyrimidines have one six-membered ring and include cytosine
(C), thymine (T), and uracil (U).
7. What type of bond links the sugars together in the backbone of DNA and RNA?
A) Hydrogen bond
B) Phosphodiester linkage
C) Peptide bond
D) Glycosidic bond
Correct Answer: Phosphodiester linkage
Expert Rationale: A phosphodiester linkage is the bond between nucleotides that links the sugar
molecules together in the backbone of DNA and RNA. Hydrogen bonds hold complementary base pairs
together, peptide bonds link amino acids in proteins, and glycosidic bonds link sugars to other
molecules.
Galen College | Q & A | 2026/2027 Edition (PDF)
1. Which of the following best describes the process by which a cell engulfs a large particle into a
vacuole?
A) Pinocytosis
B) Phagocytosis
C) Receptor-mediated endocytosis
D) Exocytosis
Correct Answer: Phagocytosis
Expert Rationale: Phagocytosis, or "cellular eating," is the process by which a cell engulfs a large particle
into a vacuole. Pinocytosis involves "cellular drinking" of extracellular fluid. Receptor-mediated
endocytosis is more specific, triggered by ligand binding, while exocytosis releases substances from the
cell.
2. What is the primary function of the sodium-potassium pump in active transport?
A) To move glucose and sodium simultaneously across the membrane
B) To move sodium and potassium ions across the cell membrane using ATP
C) To engulf extracellular fluid into tiny vesicles
D) To release cellular contents through vesicle fusion
Correct Answer: To move sodium and potassium ions across the cell membrane using ATP
Expert Rationale: The sodium-potassium pump moves sodium and potassium ions across the cell
membrane, involving the hydrolysis of ATP to produce the necessary energy. This maintains the resting
membrane potential. Co-transport moves two substances simultaneously without ATP, while
endocytosis and exocytosis are distinct processes.
3. In receptor-mediated endocytosis, what triggers the formation of a vesicle?
,A) The engulfment of a large particle
B) The "gulping" of extracellular fluid
C) The binding of a ligand to a specific receptor site
D) The fusion of a transport vesicle with the membrane
Correct Answer: The binding of a ligand to a specific receptor site
Expert Rationale: In receptor-mediated endocytosis, the binding of ligands (any molecule that binds
specifically to a receptor site) to receptors triggers vesicle formation. This process is more specific than
phagocytosis or pinocytosis. Exocytosis involves vesicle fusion with the membrane to release contents.
4. What does it mean for a carrier protein to be saturated?
A) The carrier protein has no binding sites available
B) All the binding sites on the carrier protein are occupied
C) The carrier protein is unable to transport any substances
D) The carrier protein has been denatured
Correct Answer: All the binding sites on the carrier protein are occupied
Expert Rationale: Saturated carrier proteins mean all the binding that the protein can do is used,
meaning all sides are bound up. This limits the rate of transport across the membrane. This concept is
important for understanding drug transport and absorption.
5. A researcher is studying the movement of substances across a cell membrane. Which type of
transport moves two substances simultaneously across a membrane by one protein complex without
using ATP?
A) Sodium-potassium pump
B) Primary active transport
C) Co-transport mechanism
D) Endocytosis
, Correct Answer: Co-transport mechanism
Expert Rationale: The co-transport mechanism moves two substances simultaneously across a
membrane by one protein or complex protein with no ATP activity. The sodium-potassium pump uses
ATP, and endocytosis involves vesicle formation.
6. Which of the following nitrogenous bases is classified as a purine?
A) Cytosine
B) Thymine
C) Adenine
D) Uracil
Correct Answer: Adenine
Expert Rationale: Purines are larger, consisting of a six-membered ring fused to a five-membered ring,
and include adenine (A) and guanine (G). Pyrimidines have one six-membered ring and include cytosine
(C), thymine (T), and uracil (U).
7. What type of bond links the sugars together in the backbone of DNA and RNA?
A) Hydrogen bond
B) Phosphodiester linkage
C) Peptide bond
D) Glycosidic bond
Correct Answer: Phosphodiester linkage
Expert Rationale: A phosphodiester linkage is the bond between nucleotides that links the sugar
molecules together in the backbone of DNA and RNA. Hydrogen bonds hold complementary base pairs
together, peptide bonds link amino acids in proteins, and glycosidic bonds link sugars to other
molecules.
