Question

Which of the following statements regarding exocytosis is correct?

• A. Is always employed by cells for secretion
• B. Is used to deliver material into the extracellular space
• C. Takes up large molecules from the extracellular space
• D. Allows the retrieval of elements of the plasma membrane

Answer 1

Answer: (A), (B)

Is used to deliver material into the extracellular space

Exocytosis provides a means for cells to deliver material to the extracellular space and to insert new material into the plasma membrane. Lipophilic molecules (e.g. steroids) are secreted directly across the plasma membrane. The retrieval of the plasma membrane and the uptake of molecules from the extracellular space both occur by endocytosis.