Question

What purpose(s) does endoplasmic reticulum serve in a cell?

• A. It is involved in intracellular transport
• B. It protects the internal organelles
• C. It provides attachment sites for ribosomes
• D. It provides increased surface area inside the cell

Answer 1

Answer: (A), (C), (D)

It provides increased surface area inside the cell

The endoplasmic reticulum (ER) is an organelle found in the cells of eukaryotic organisms. It is an interconnected network of flattened sacs or tubes encased in membranes.
Endoplasmic reticulum has two types, rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). Rough ER is studded with ribosome, the site of protein synthesis. Smooth ER doesn't have ribosome and is very important to the process of metabolism.
Endoplasmic reticulum has a number of jobs within the cell. This includes the folding and transport of various proteins, specifically carrying them to the Golgi apparatus. Some other proteins, mostly the glycoproteins, move across the ER's membrane. The ER is also responsible for marking these proteins that it transports with a signal sequence. Other proteins are headed outside the ER, so they are packed into transport vesicles and moved out of the cell via the cytoskeleton.