Answer: Move laterally within the bilayer (lateral diffusion) but rarely flip.
- A Flip rapidly and frequently between the inner and outer leaflets of the bilayer
- B Move laterally within the bilayer (lateral diffusion) but rarely flip
- C Remain permanently fixed in one position without any lateral movement
- D Diffuse rapidly across the bilayer's hydrophobic core within milliseconds
Correct answer: B. Move laterally within the bilayer (lateral diffusion) but rarely flip
Explanation: Phospholipids diffuse rapidly laterally within their leaflet but rarely flip (transverse diffusion/flip-flop). Proteins also move laterally.
Animal cell structure with major organelles labeled. Image: LadyofHats (Mariana Ruiz), Public Domain, via Wikimedia Commons.
Concept context
Cell theory, prokaryotic vs eukaryotic cells, organelles and their functions. Foundation of all biology.