MCQ: the plasma membrane

1. What is the primary function of the plasma membrane in a living cell?
a) To maintain a rigid structure
b) To control the exchange of substances with the environment
c) To produce energy for the cell
d) To store genetic information

2. Which model revolutionized the understanding of the plasma membrane’s structure and dynamics?
a) The Fluid Mosaic Model
b) The Rigid Bilayer Model
c) The Dynamic Structure Model
d) The Lipid-Protein Model

3. Which of the following is NOT a component of the chemical composition of the plasma membrane?
a) Lipids
b) Proteins
c) Nucleic acids
d) Carbohydrates

4. The lipid bilayer of the plasma membrane is primarily held together by:
a) Hydrogen bonds
b) Electrostatic interactions
c) Hydrophobic interactions
d) Covalent bonds

5. Which of the following lipids types is considered the lipid bilayer’s backbone?
a) Glycolipids
b) Sterols
c) Phospholipids
d) Sphingolipids

6. What is the function of glycolipids in the plasma membrane?
a) They provide rigidity to the membrane.
b) They facilitate the passive movement of molecules.
c) They mediate specific cell-cell adhesion events.
d) They control the exchange of substances with the environment.

7. Which lipid molecule plays a role in maintaining fluidity by interacting differently at higher and lower temperatures?
a) Glycerol
b) Sphingolipid
c) Cholesterol
d) Sterol

8. What is the role of transporter proteins in the plasma membrane?
a) They assist in forming lipid rafts.
b) They maintain the fluid mosaic structure.
c) They facilitate the passive movement of molecules.
d) They enable the movement of molecules across the membrane.

9. The asymmetry of the lipid bilayer is regulated by:
a) Fast trans bilayer diffusion
b) Lateral diffusion
c) Protein-mediated transport
d) Only the outer leaflet composition

10. What is the significance of lipid rafts in the plasma membrane?
a) They mediate the synthesis of carbohydrates.
b) They help maintain the rigid structure of the bilayer.
c) They assist in cholesterol transport.
d) They play roles in signal transduction and endocytosis.

11. Which structure is responsible for allowing hydrophilic solutes to traverse the plasma membrane?
a) Lipid rafts
b) Glycolipids
c) Transmembrane proteins with beta-barrel structures
d) Integral proteins with hydrophobic side chains

12. What role do sterols, such as cholesterol, play in the plasma membrane?
a) They provide rigidity to the membrane.
b) They catalyze lipid synthesis.
c) They mediate protein-ligand interactions.
d) They facilitate active transport processes.

13. Which technique can be used to visualize the lateral movement of lipid molecules in the plasma membrane?
a) ELISA
b) Western blotting
c) FRAP (Fluorescence Recovery After Photobleaching)
d) PCR (Polymerase Chain Reaction)

14. The fluidity of the plasma membrane is influenced by the following:
a) Nucleic acids
b) Temperature and lipid composition
c) Carbohydrate concentration
d) Peripheral proteins

15. What is the main purpose of the cell coat and glycocalyx on cell surfaces?
a) To provide rigidity to the plasma membrane
b) To mediate specific cell-cell adhesion events
c) To maintain the fluidity of the bilayer
d) To enhance cellular respiration