Multiple Choice Questions on Membrane Transport MCQ

1. Gases such as oxygen and carbon dioxide cross the cell membrane by

a) passive diffusion through the lipid bilayer

b) primary active transport

c) specific gas transport proteins

d) secondary active transport

2.Carrier proteins take part in

a)Water transport

b)Active transport of ions

c)Passive transport of ions

d)None of these

3. Which of the following is an example of primary active transport?

a)Cl^--HCO₃^- exchange
b)Na⁺ K⁺ ATPase

c)Na⁺ - H⁺ exchange

d)Na⁺-Ca²⁺ exchange

4. The principal intracellular cation is:
a)Na⁺
b)Ca⁺
c)K⁺
d)Cl^-

5. The sodium pump
a)Exchanges extracellular Na⁺ for intracellular K⁺
b)Is an ion channel
c)Is important for maintaining a constant cell volume
d)Can only be inhibited by metabolic poisons

6.  Which of the following values is closest to the resting membrane potential of mammalian cells:
a)+20 mV
b)-20 mV
c)-60 mV
d)+60 mV

7. Which of the following statements regarding exocytosis is correct?
a)Is always employed by cells for secretion
b)Takes up large molecules from the extracellular space
c)Allows the retrieval of elements of the cell membrane
d)Is used to deliver material into the extracellular space

8. Endocytosis is used by cells to:
a)Ingest bacteria and cell debris
b)Retrieve elements of the cell membrane after exocytosis
c)Secrete largely molecules into the extracellular space
d)None of these

9.  Pinocytosis

a)At sites of membrane called coated pits.

b)For large protein molecule

c)By formation of the pinocytic vesicle.

d)All of these

10. The resting membrane potential is mainly determined by:
a)the K⁺ gradient
b)the Cl^- gradient
c)the Ca²⁺ gradient
d)the Na⁺ gradient

11. Which of the following process requires membrane proteins?

a)Pinocytosis
b)exocytosis

c)Phagocytosis

d)Receptor-mediated endocytosis

12. Phagocytosis

a)Is preceded by opsonization

b)Requires the presence of Ca²⁺ ions in extracellular fluid.
c)Occurs mainly in leucocytes

d)All of these

13. The small polar molecules, ions and macromolecules (proteins and RNAs) can travel between the nucleus and the cytoplasm through

a) Membrane Channels

b) Inter membrane transporters

c) Transporters like Kinesin

d)Nuclear pore complexes

14. The fluidity of a phospholipid bilayer depends on:

 1. Chain length of the fatty acid  2. Glycoprotein content of the lipid bilayer 

 3. Degree of unsaturation of fatty acid   4. Carbohydrate content of the lipid bilayer . 

a) 1 only 

b) 1 & 3 only 

c) 2 only

d) 1 & 2 only        

15. Membrane carrier proteins differ from membrane channel proteins by 

a) Carrier proteins are glycoproteins and channel proteins are lipoproteins 

b) Channel proteins can mediate active transport, but carrier proteins cannot 

c) Carrier proteins can mediate active transport, but channel proteins cannot 

d) Carrier proteins are synthesized by free ribosomes, but channel proteins are synthesized by bound ribosomes 

Learn more: 

• Notes on Membrane Transport- Passive and Active Transport
• Notes on Exocytosis and Endocytosis (Phagocytosis, Pinocytosis and Receptor-Mediated endocytosis)
• Quiz on Cell Membrane (Plasma Membrane)

Answers:
1.a) passive diffusion through the lipid bilayer
2. b)Active transport of ions
3. b)Na⁺ K⁺ ATPase
4. c)K⁺
5. c)Is important for maintaining a constant cell volume
6. c)-60 mV
7. d)Is used to deliver material into the extracellular space
8. b)Retrieve elements of the cell membrane after exocytosis
9. d)All of these
10. a)the K⁺ gradient
11. d)Receptor-mediated endocytosis
12. d)All of these

13. d) Nuclear pore complexes

14. b) 1 & 3 only 

15. c) Carrier proteins can mediate active transport, but channel proteins cannot