NUR 4909 Membrane Transport Exam
(2026–2027): Advanced Nursing
Physiology Review with Correct Answers
1. The opening of membrane channels can be controlled by “gates.” What factors
can cause these gates to open?
• CORRECT ANSWER>>>– Mechanical stimulation – Ligand binding – Change
in membrane voltage
2. Name three functions of the sodium-potassium pump.
• CORRECT ANSWER>>>– Maintain ionic gradients (important to resting
potential) – Provides gradients for secondary active
transporters – Maintains cell volume by keeping ionic concentrations
constant
3. How do passive transport and active transport differ?
• CORRECT ANSWER>>>– Active transport requires ATP, passive does
not – Active moves a substance against its concentration gradient, while
passive moves a substance down its concentration gradient
4. Is facilitated diffusion active or passive?
• CORRECT ANSWER>>>– Passive
5. If the vessels of the brain have a reduced amount of plasma proteins, what
effect would you expect this to have on the volume of extracellular fluid
surrounding the brain neurons?
, • CORRECT ANSWER>>>– Decrease in plasma proteins reduces colloid
osmotic pressure, leading to decreased reabsorption of interstitial fluid;
therefore extracellular fluid volume surrounding neurons would increase
(edema).
6. What is the primary structural component of the cell membrane?
• CORRECT ANSWER>>>– Phospholipid bilayer with embedded proteins
7. Describe the fluid mosaic model of the cell membrane.
• CORRECT ANSWER>>>– The membrane is a dynamic structure in which
phospholipids and proteins move laterally; proteins are embedded within
or attached to the lipid bilayer, creating a “mosaic.”
8. Which types of molecules can diffuse directly through the lipid bilayer without
assistance?
• CORRECT ANSWER>>>– Small nonpolar molecules (e.g., oxygen, carbon
dioxide) and lipids (e.g., steroid hormones)
9. What is the role of cholesterol in the cell membrane?
• CORRECT ANSWER>>>– Cholesterol modulates membrane fluidity and
stability; it prevents the membrane from becoming too rigid at low
temperatures and too fluid at high temperatures.
10. Distinguish between integral (transmembrane) proteins and peripheral
membrane proteins.
• CORRECT ANSWER>>>– Integral proteins span the lipid bilayer and are
involved in transport, signaling, or cell adhesion; peripheral proteins are
, attached to the membrane surface and often participate in signaling or
cytoskeletal anchoring.
11. What is the difference between simple diffusion and facilitated diffusion?
• CORRECT ANSWER>>>– Simple diffusion moves substances directly
through the lipid bilayer; facilitated diffusion uses carrier proteins or
channel proteins to move substances down their concentration gradient.
12. Give two examples of molecules that enter cells via facilitated diffusion.
• CORRECT ANSWER>>>– Glucose (via GLUT transporters) – Ions (via ion
channels)
13. What is the defining characteristic of primary active transport?
• CORRECT ANSWER>>>– Direct hydrolysis of ATP (or another energy
source) to transport a substance against its concentration gradient.
14. Name one primary active transporter besides the Na⁺/K⁺ ATPase.
• CORRECT ANSWER>>>– Ca²⁺ ATPase (calcium pump) – H⁺ ATPase (proton
pump) – H⁺/K⁺ ATPase
15. Describe secondary active transport.
• CORRECT ANSWER>>>– Uses the energy stored in an ion gradient (usually
Na⁺) established by primary active transport to co-transport another
substance against its gradient.
16. Differentiate between symport and antiport.
(2026–2027): Advanced Nursing
Physiology Review with Correct Answers
1. The opening of membrane channels can be controlled by “gates.” What factors
can cause these gates to open?
• CORRECT ANSWER>>>– Mechanical stimulation – Ligand binding – Change
in membrane voltage
2. Name three functions of the sodium-potassium pump.
• CORRECT ANSWER>>>– Maintain ionic gradients (important to resting
potential) – Provides gradients for secondary active
transporters – Maintains cell volume by keeping ionic concentrations
constant
3. How do passive transport and active transport differ?
• CORRECT ANSWER>>>– Active transport requires ATP, passive does
not – Active moves a substance against its concentration gradient, while
passive moves a substance down its concentration gradient
4. Is facilitated diffusion active or passive?
• CORRECT ANSWER>>>– Passive
5. If the vessels of the brain have a reduced amount of plasma proteins, what
effect would you expect this to have on the volume of extracellular fluid
surrounding the brain neurons?
, • CORRECT ANSWER>>>– Decrease in plasma proteins reduces colloid
osmotic pressure, leading to decreased reabsorption of interstitial fluid;
therefore extracellular fluid volume surrounding neurons would increase
(edema).
6. What is the primary structural component of the cell membrane?
• CORRECT ANSWER>>>– Phospholipid bilayer with embedded proteins
7. Describe the fluid mosaic model of the cell membrane.
• CORRECT ANSWER>>>– The membrane is a dynamic structure in which
phospholipids and proteins move laterally; proteins are embedded within
or attached to the lipid bilayer, creating a “mosaic.”
8. Which types of molecules can diffuse directly through the lipid bilayer without
assistance?
• CORRECT ANSWER>>>– Small nonpolar molecules (e.g., oxygen, carbon
dioxide) and lipids (e.g., steroid hormones)
9. What is the role of cholesterol in the cell membrane?
• CORRECT ANSWER>>>– Cholesterol modulates membrane fluidity and
stability; it prevents the membrane from becoming too rigid at low
temperatures and too fluid at high temperatures.
10. Distinguish between integral (transmembrane) proteins and peripheral
membrane proteins.
• CORRECT ANSWER>>>– Integral proteins span the lipid bilayer and are
involved in transport, signaling, or cell adhesion; peripheral proteins are
, attached to the membrane surface and often participate in signaling or
cytoskeletal anchoring.
11. What is the difference between simple diffusion and facilitated diffusion?
• CORRECT ANSWER>>>– Simple diffusion moves substances directly
through the lipid bilayer; facilitated diffusion uses carrier proteins or
channel proteins to move substances down their concentration gradient.
12. Give two examples of molecules that enter cells via facilitated diffusion.
• CORRECT ANSWER>>>– Glucose (via GLUT transporters) – Ions (via ion
channels)
13. What is the defining characteristic of primary active transport?
• CORRECT ANSWER>>>– Direct hydrolysis of ATP (or another energy
source) to transport a substance against its concentration gradient.
14. Name one primary active transporter besides the Na⁺/K⁺ ATPase.
• CORRECT ANSWER>>>– Ca²⁺ ATPase (calcium pump) – H⁺ ATPase (proton
pump) – H⁺/K⁺ ATPase
15. Describe secondary active transport.
• CORRECT ANSWER>>>– Uses the energy stored in an ion gradient (usually
Na⁺) established by primary active transport to co-transport another
substance against its gradient.
16. Differentiate between symport and antiport.
