Which structure is involved in modifying proteins before they are sent to their destination in eukaryotic cells?

The Golgi apparatus is a critical organelle in eukaryotic cells responsible for modifying, sorting, and packaging proteins for secretion or delivery to other organelles. After proteins are synthesized in the ribosomes and enter the endoplasmic reticulum, they are transported to the Golgi apparatus in vesicles.

Within the Golgi apparatus, proteins undergo various modifications, which may include glycosylation (the addition of carbohydrate groups), phosphorylation, or cleavage. These modifications are essential for the proteins to function correctly or to be targeted to the appropriate cellular location. Once the processing is complete, the Golgi apparatus then sorts these proteins and dispatches them in new vesicles, directing them to their final destinations within or outside the cell.

This makes the Golgi apparatus a fundamental component of the cellular machinery that ensures proteins are correctly processed and delivered, integral to maintaining the function and structure of the cell.