In which organelle (s) of hepatocyte, the elongation of long chain fatty acid takes place?

There is two kinds of endoplasmic reticulum (ER): (i) Rough surfaced ER, also known as ergastoplasm. They are coated with ribosomes. Near the nucleus, this type of ER merges with the outer membrane of the nuclear envelope. (ii) Smooth surfaced ER: They do not have attached ribosomes. Function of smooth ER: Smooth endoplasmic reticulum is involved: (i) In lipid synthesis and (ii) Modification and transpo of proteins synthesised in the rough ERRef: M.N. Chatterjea - Textbook of Biochemistry, 8th edition, page no: 7