[Campbell Biology P.189] According to the provided diagram and text, what is the primary fun... | Practice Question

According to the provided diagram and text, what is the primary function of "coat proteins" and the resulting "coated pits" or "coated vesicles" in endocytosis?

  • A: To enable the cell to engulf large food particles.
  • B: To provide structural support for the infolding of the plasma membrane and the formation of vesicles.
  • C: To directly bind specific solutes from the extracellular fluid.
  • D: To digest the contents once they are inside the cell.

Explanation

The text for pinocytosis states: "the parts of the plasma membrane that form vesicles are lined on their cytoplasmic side by a fuzzy layer of coat protein; the 'pits' and resulting vesicles are called coated pits." Similarly, for receptor-mediated endocytosis, "The receptor proteins then cluster in coated pits, and each coated pit forms a vesicle." This indicates their role in the structural formation and stabilization of the infoldings and vesicles.