plasma membrane replentishing Question

[NewtoBiology]

Hello biologists,

Q: which of the following cells are most likely to be engaged in continually replacing membrane from its plasma membrane, and erythrocyte, a pancreatic acinar cell, or a macrophage? Why?

A: I always try to do my own work first and then double check when I am totally confused.

erythrocyte: NO, these are simply red blood cells and do not need to replentish their membrane, as they dont loose any of it on a continual basis.

pancreatic acinar cell: these cells are secretory cells, therefore I believe the cells would continually engage in exocytosis. Because the contents within the cell are being expelled, the membrane opens and fuses with the vesicle membrane. Therefore the cell is actually getting 'larger' and doesn't need more replacing.

macrophage: these cells engage in phagocytosis, therefore because they are continually engulfing things from the extracellular space, they would need to replace their membrane otherwise they would continue to become smaller and smaller.

Am I correct in choosing the macrophage, or is it the complete opposite and the correct answer is the pancreatic acinar cell. Oooooooooh so confused.

Thank you for your help,

Newtobiology

[MrMistery]

you're not confused, you reasoned through everything quite well. Nice job