試題詳解

33. Cholesterol plays a crucial role in maintaining the fluidity and stability of cell membranes. Which of the following best describes how cholesterol contributes to membrane stability under varying temperature conditions?
(A) Cholesterol forms strong covalent bonds with phospholipids, rigidifying the membrane at all temperatures.
(B) Cholesterol intercalates between phospholipids, preventing them from packing too tightly at low temperatures and preventing excessive fluidity at high temperatures.
(C) Cholesterol increases the hydrophobicity of the membrane, reducing water permeability and stabilizing the bilayer.
(D) Cholesterol interacts with membrane proteins, anchoring them to the membrane and preventing lateral movement.
(E) Cholesterol directly regulates the activity of membrane transport proteins, influencing the movement of ions and molecules across the membrane.