a sentence using exocytosis and endocytosis

Read the following site and then you can easily formulate such sentences:
http://en.wikipedia.org/wiki/Endocytosis

thanks

Exocytosis and endocytosis are both cellular processes involved in the transportation of molecules in and out of the cell.

Here's an example sentence: "During exocytosis, the cell releases neurotransmitters into the synaptic cleft to transmit signals to neighboring cells, while during endocytosis, the cell internalizes nutrients by engulfing them in vesicles."