Cell Membrane & Transport — Cellular & General Physiology

Cell Membrane & Transport MCQs: practice questions

Sample Cell Membrane & Transport multiple-choice questions from Cellular & General Physiology.

1. A transport protein recognizes D-glucose but not its L-isomer. This demonstrates:

   • A. Osmotic pressure
   • B. Saturation
   • C. Stereospecificity
   • D. Electroneutrality
   • E. Bulk flow

2. Na+ and glucose enter an intestinal epithelial cell through the same carrier in the same direction. This is:

   • A. Symport
   • B. Simple diffusion
   • C. Countertransport
   • D. Primary active transport
   • E. Channel diffusion

3. Which membrane transport process can move a substance against its electrochemical gradient when directly coupled to ATP hydrolysis?

   • A. Primary active transport
   • B. Facilitated diffusion
   • C. Simple diffusion
   • D. Osmosis
   • E. Filtration

4. Two solutions separated by a membrane have equal effective osmotic pressures. They are best described as:

   • A. Hypertonic
   • B. Hypotonic
   • C. Hyposmotic
   • D. Hyperosmotic
   • E. Isotonic

5. Which statement best describes primary active transport?

   • A. Moves solute downhill without a carrier
   • B. Uses only the Na+ gradient
   • C. Always transports two solutes together
   • D. Uses ATP directly to move solute uphill
   • E. Requires no metabolic energy

6. Which drug class directly inhibits the gastric H+,K+-ATPase?

7. Which feature distinguishes simple diffusion from carrier-mediated transport?

8. A 1 M NaCl solution is assumed to dissociate completely. Its calculated osmolarity is approximately:

9. Which plasma protein property makes albumin an effective osmole across a membrane that is poorly permeable to it?

10. A hydrophilic ion crosses a membrane primarily through:

11. Which property of carrier-mediated transport causes transport to plateau at high solute concentrations?

12. A membrane protein spans the lipid bilayer and functions as an ion channel. It is best classified as a:

13. A solute moves across a membrane down its electrochemical gradient through a specific carrier without ATP use. What process is this?

14. The usual stoichiometry of the Na+–K+ pump is:

15. Na+ and Ca2+ move through an exchanger in opposite directions. This is:

16. A cell placed in a solution containing a nonpenetrating solute at a higher effective concentration than the cell will initially:

17. A solute has a reflection coefficient of 1.0. Compared with a solute with a coefficient of 0, it will:

18. Which change would most directly increase membrane permeability to a solute?

19. A receptor-mediated endocytic pathway is especially useful because it:

20. Two structurally related sugars compete for the same carrier. Which characteristic of carrier transport is demonstrated?

21. A secretory vesicle fuses with the plasma membrane and releases its contents outside the cell. This is:

22. Which membrane process allows a cell to engulf a large extracellular particle?

23. Which membrane component forms the hydrophobic core of the cell membrane?

24. Which change would increase diffusion across a membrane, assuming other factors remain constant?

25. A patient has a defect in the Na+–glucose cotransporter of the proximal tubule. Which mechanism is directly impaired?

26. Water crosses a semipermeable membrane from a solution with lower effective osmotic pressure toward one with higher effective osmotic pressure. This is:

27. Urea has a reflection coefficient close to zero. What does this imply?

28. Inhibition of the Na+–K+ pump would most directly reduce which process?

29. Which substance would cross a lipid bilayer most readily by simple diffusion?

30. Which solute generally has the highest permeability through a lipid membrane?