Question

which type of endoplasmic reticulum is involved in modifying proteins?
rough er
smooth er

Explanation:

The rough endoplasmic reticulum (Rough ER) has ribosomes attached to its surface. These ribosomes synthesize proteins, and the Rough ER is involved in protein - folding and initial modifications of newly synthesized proteins. The smooth endoplasmic reticulum (Smooth ER) is mainly involved in lipid synthesis and detoxification processes, not protein modification.

Answer:

Rough ER