Question

Proteins destined for extracellular release are packaged in specific vesicles. After packaging, the vesicles bud off and are stored in the cell until a signal is given for their release. When the appropriate signal is received they move towards the membrane and fuse to release their contents. Once proteins have been produced at the ribosomes, what two organelles work together to aid in the secretion process described above? A) ribosome and ER B) Golgi apparatus and rough ER C) Golgi apparatus and lysosome D) mitochondria and rough endoplasmic reticulum

Answer 1

Proteins are produced inside the rough ER (it's "rough" because of its appearance under electron microscopy, because of all the ribosomes that are attached to the outside translating proteins into it). This is where the proteins are initially packaged into vesicles, which then move into the Golgi apparatus (where they undergo various post-translational modifications). From the Golgi apparatus the vesicles move to and fuse with the membrane and release their contents to the outside of the cell (i.e. exocytosis).

Answer is B.

Golgi apparatus must be part of your answer here because it's where exocytosis signals are received as the question describes. C is wrong because lysosomes are more so involved in degrading old proteins and other cell contents, not exocytosis.