[Campbell Biology P.190] As a cell grows and its plasma membrane expands, which cellular pro... | Practice Question
As a cell grows and its plasma membrane expands, which cellular process is primarily responsible for adding new membrane material?
Explanation
As stated in the text, 'Endocytosis and exocytosis also provide mechanisms for rejuvenating or remodeling the plasma membrane. These processes occur continually in most eukaryotic cells, yet the amount of plasma membrane in a nongrowing cell remains fairly constant. The addition of membrane by one process appears to offset the loss of membrane by the other.' Exocytosis is the process by which vesicles fuse with the plasma membrane, releasing their contents outside the cell and adding the vesicle membrane to the plasma membrane, thus expanding it.