Which of the following structures is involved in packaging proteins?

The Golgi apparatus plays a crucial role in the processing and packaging of proteins within the cell. Once proteins are synthesized in the endoplasmic reticulum, they are transported to the Golgi apparatus, where they undergo further modifications, such as adding carbohydrate or lipid groups. This processing ensures that proteins are correctly folded and fully functional.

After modifications, the Golgi apparatus packages these proteins into vesicles, which then transport them to their specific destinations—either inside the cell or outside of it through secretion. This organization is essential for maintaining proper cellular function and communication.

The nucleus is primarily responsible for housing genetic material and controlling cellular activities, while mitochondria are involved in energy production through respiration. Chloroplasts are specific to plant cells and are involved in photosynthesis, converting light energy into chemical energy. Thus, the Golgi apparatus is uniquely suited for the task of packaging proteins, making it the correct choice.