[Campbell Biology P.154] Which sequence accurately describes the path of a secretory protein... | Practice Question

Which sequence accurately describes the path of a secretory protein from its synthesis to its departure from the endoplasmic reticulum system?

  • A: Free ribosome → Cytosol → Transport vesicle → Golgi apparatus.
  • B: Rough ER ribosome → ER lumen (folding) → Transitional ER → Transport vesicle.
  • C: Smooth ER → Transport vesicle → Golgi apparatus.
  • D: Nucleus → Rough ER lumen → Lysosome.

Explanation

As described in the 'Functions of Rough ER' section, secretory proteins grow from bound ribosomes, are threaded into the ER lumen where they fold, and then depart from the transitional ER in transport vesicles.