Which organelle is responsible for modifying, sorting, and packaging proteins for secretion?

• A. Endoplasmic Reticulum
• B. Nucleus
• C. Golgi apparatus
• D. Lysosome

Answer: (C)

Proteins destined for secretion are processed and routed in the cell’s secretory pathway. After being made and folded in the rough endoplasmic reticulum, these proteins travel to the Golgi apparatus, where they receive further modifications and are sorted and packaged into vesicles for secretion. The Golgi then directs each protein to its correct destination, packaging them for release outside the cell when the vesicles fuse with the plasma membrane. The nucleus stores genetic material and controls cellular activities, but does not participate in post-translational processing or packaging of secreted proteins. The lysosome contains enzymes for digestion, not for packaging secreted proteins. The endoplasmic reticulum handles initial protein synthesis and folding, while the Golgi handles the final modifications, sorting, and packaging for secretion.