Which organelle processes and packages proteins from the ER for secretion or delivery to other compartments?

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

Answer: (A)

The Golgi apparatus acts as the cell’s processing and shipping center for proteins that come from the ER. After proteins are synthesized and folded in the endoplasmic reticulum, they’re packaged into vesicles and delivered to the Golgi. Inside the Golgi, enzymes modify those proteins (such as adding or trimming sugar groups), quality control checks occur, and then the proteins are sorted and packed into new vesicles at the trans face. These vesicles carry the proteins to their final destinations—secreted outside the cell, incorporated into the cell membrane, or sent to lysosomes or other compartments. The other organelles have different roles—protein synthesis and folding in the ER, degradation in lysosomes, or photosynthesis in chloroplasts—so the Golgi is the one that processes, tags, and packages proteins for secretion or delivery.