Once the protein products are packaged in the endoplasmic reticulum into vesicles that fuse to the Golgi apparatus, these protein products are modified by enzymes. These changes are called post-translational modifications and include the addition of carbohydrates, lipids or some other functional groups. All these modifications are key for protein functionality. After this process is concluded, functional proteins are packaged into vesicles and released to their final destination inside or outside the cell.
