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

• A. Mitochondria generate energy for the cell
• B. Rough endoplasmic reticulum synthesizes lipids
• C. Golgi apparatus modifies, sorts, and packages proteins for secretion or delivery
• D. Lysosomes digest cellular waste

Answer: (C)

Proteins destined for secretion or delivery are processed in a specific shipping center of the cell. After synthesis in the rough endoplasmic reticulum, these proteins arrive at the Golgi apparatus, where they receive finishing touches such as carbohydrate modifications, are tagged with the correct address, and are packaged into vesicles for export or delivery to their final locations. This organization—the modification, sorting, and packaging step—is what the Golgi apparatus specializes in. Mitochondria provide energy for the cell, the rough endoplasmic reticulum makes and folds proteins but passes them on for final processing to the Golgi, and lysosomes break down cellular waste.