Final answer:
The correct order for protein secretion from a cell is rough endoplasmic reticulum, Golgi apparatus, then plasma membrane. This involves synthesis, modification, and sorting before secretion or integration into the membrane.
Step-by-step explanation:
The correct sequence for an altered protein that is secreted from the cell is rough endoplasmic reticulum - Golgi apparatus - plasma membrane. This process begins when membrane and secretory proteins are synthesized on bound ribosomes in the lumen of the rough endoplasmic reticulum (RER). The RER may also modify these proteins. Proteins are then packed into vesicles that bud from the ER and subsequently fuse with the Golgi apparatus' cis face. During their transit through the Golgi apparatus, proteins undergo further modifications, including carbohydrate attachment. Finally, the proteins are sorted into vesicles that bud from the trans face of the Golgi and are then dispatched to their final destinations, including fusion with the plasma membrane where they may be secreted out of the cell or become an integral part of the cell membrane.