Final answer:
The rough endoplasmic reticulum gets its name from the ribosomes that are attached to it, creating a rough appearance. These ribosomes are essential for protein synthesis in the cell, leading to protein transport to various locations including the Golgi apparatus.
Step-by-step explanation:
The rough endoplasmic reticulum (RER) is so called because ribosomes stud the surface of that organelle, giving it a characteristic studded or 'rough' appearance. This appearance is most notable when the RER is observed through an electron microscope. The primary function of these ribosomes is to synthesize proteins which are then transported within the cell in transport vesicles. These vesicles can then move to the Golgi apparatus, integrate into the cell membrane, or be secreted out of the cell.
The membrane of the RER is continuous with the outer layer of the nuclear envelope, highlighting its integral role in protein synthesis and transport within the cell. In contrast, the smooth endoplasmic reticulum (SER), which lacks ribosomes, is involved in functions like lipid synthesis, calcium ion storage, and drug detoxification.