Which of the following events does not occur in rough endoplasmic reticulum?
Answer: (D) Phospholipid synthesis. Answer: (D) Phospholipid synthesis Solution: The rough endoplasmic reticulum bears ribosomes and is the site of protein synthesis and associated co/post-translational steps (signal peptide cleavage, glycosylation, folding).
- A.Cleavage of signal peptide
- B.Protein glycosylation
- C.Protein folding
- D.Phospholipid synthesis✓
Correct Answer
(D) Phospholipid synthesis
Solution & Explanation
Answer: (D) Phospholipid synthesis Solution: The rough endoplasmic reticulum bears ribosomes and is the site of protein synthesis and associated co/post-translational steps (signal peptide cleavage, glycosylation, folding). Phospholipid (lipid) synthesis is the function of the SMOOTH ER, not the RER, so it does NOT occur in the rough ER. NCERT explicitly assigns lipid synthesis to the SER while RER is linked to protein synthesis and secretion. NCERT Reference: Ch 8, p.95, lines 49–51: "The smooth endoplasmic reticulum is the major site for synthesis of lipid. In animal cells lipid-like steroidal hormones are synthesised in SER."