A cell biologist compared the properties of rough endoplasmic reticulum (ER) and smooth ER. She found that one type of ER is used for protein storage, and the other is used for lipid storage. What accounts for this difference?

Question

a
Rough ER has ribosomes on its surface.
b
Rough ER forms proteins and transports them to the mitochondria.
c
Smooth ER creates amino acids for ribosomes to form into proteins.
d
Smooth ER works with the nucleus to synthesize protein.

Answer 1

The correct answer to explain the difference between rough ER and smooth ER in terms of their functions is:

a. Rough ER has ribosomes on its surface.

The rough endoplasmic reticulum (rough ER) is studded with ribosomes on its cytoplasmic surface, which are the sites of protein synthesis. This makes rough ER primarily involved in the synthesis and storage of proteins. In contrast, the smooth endoplasmic reticulum (smooth ER) lacks ribosomes and is involved in lipid synthesis and storage, as well as various metabolic processes.