[Campbell Biology P.189] A mammalian cell needs to import cholesterol, a crucial lipid, from... | Practice Question

A mammalian cell needs to import cholesterol, a crucial lipid, from the extracellular fluid, where it is present at very low concentrations. Based on the provided types of endocytosis, which pathway would be most effective for the cell to acquire this specific and scarce nutrient?

  • A: Phagocytosis.
  • B: Pinocytosis.
  • C: Receptor-mediated endocytosis.
  • D: Exocytosis.

Explanation

Receptor-mediated endocytosis is described as a "specialized type of pinocytosis that enables the cell to acquire bulk quantities of specific substances, even though those substances may not be very concentrated in the extracellular fluid." This mechanism uses specific receptors to bind and concentrate the desired molecules, making it highly efficient for acquiring scarce, specific nutrients like cholesterol.