Match the eukaryotic cellular organelles listed in Column Y with their typical function from among those listed in Column Y.

Column X organelles		Column Y function
A.	Golgi	I.	Ribosomes assembly
B.	Nucleolus	II.	O-linked Glycosylation
C.	Peroxisomes	III.	Ste for lipid synthesis
D.	ER	IV.	Oxygen utilization

​Which one of the following options represents all correct matches between Column X and Column Y?​

Correct option is B

1. Golgi Apparatus (A - ii) → O-linked Glycosylation

• The Golgi apparatus is a membrane-bound organelle responsible for protein processing and modification.
• One of its primary roles is O-linked glycosylation, which involves adding sugar molecules to oxygen atoms of serine or threonine residues in proteins.
• This modification is crucial for protein stability, folding, and function.
• Proteins undergo initial glycosylation in the endoplasmic reticulum (ER) but O-linked glycosylation is specifically performed in the Golgi.

2. Nucleolus (B - i) → Ribosome Assembly

• The nucleolus is a non-membranous structure located inside the nucleus.
• It is the site where ribosomal RNA (rRNA) is synthesized and ribosome subunits are assembled.
• Ribosomes are essential for protein synthesis, and their production in the nucleolus is critical for cellular function.
• The assembled ribosomal subunits are later transported to the cytoplasm, where they participate in translation.

3. Peroxisomes (C - iv) → Oxygen Utilization

• Peroxisomes are small, membrane-bound organelles involved in oxidative metabolism.
• They utilize oxygen to break down fatty acids (beta-oxidation) and detoxify harmful substances.
• A key enzyme present in peroxisomes is catalase, which breaks down hydrogen peroxide (H₂O₂) into water and oxygen.
• Unlike mitochondria, peroxisomes do not generate ATP, but they play a major role in lipid metabolism and oxygen-dependent reactions.

4. Endoplasmic Reticulum (ER) (D - iii) → Site for Lipid Synthesis

• The Endoplasmic Reticulum (ER) is divided into:
  • Rough ER (RER): Studded with ribosomes, responsible for protein synthesis.
  • Smooth ER (SER): Lacks ribosomes and is the primary site of lipid and steroid synthesis.
• The Smooth ER is specifically involved in:
  • Synthesis of phospholipids and cholesterol (important for membrane formation).
  • Detoxification of drugs and poisons (especially in liver cells).
  • Regulation of calcium levels in muscle cells.
• Since lipid synthesis occurs in the ER, this matches with option (iii).