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

Answer 1

The correct answer is:

b. Rough ER has ribosomes on its surface.

The rough endoplasmic reticulum (Rough ER) is studded with ribosomes, which are responsible for synthesizing proteins. In contrast, smooth endoplasmic reticulum (Smooth ER) does not have ribosomes and is involved in lipid synthesis and storage, as well as other functions such as detoxification and calcium ion storage. Thus, the presence of ribosomes on the Rough ER accounts for its function in protein synthesis and transport, while the lack of ribosomes on the Smooth ER relates to its role in lipid metabolism.