Final answer:
Transverse diffusion in living biological membranes is more frequent than in artificial bilayers because of the action of specialized enzymes like lipases and scramblases and factors influencing membrane fluidity.
Step-by-step explanation:
In living biological membranes, transverse diffusion (flip-flop) of phospholipids occurs more frequently than in artificial bilayers due to the presence of specialized enzymes known as lipases and scramblases. These enzymes facilitate the movement of lipid molecules from one leaflet of the bilayer to the other. In contrast, artificial bilayers lack these proteins, making flip-flop movements rare. Furthermore, the fluidity of the membrane, which is influenced by factors like cholesterol content and types of fatty acids in the phospholipids, can also impact the rate of transverse diffusion.