This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Structure & Function of Proteins), Subject name: Biochemistry
Agranular cytoplasmic reticulum is involved in the synthesis of 
Select and explain. 
A. Protein, B. Lipid, C. Vitamin, D. Carbohydrate
B: Lipid
Answer: B: Lipid 
Explanation: Ans. is 'b' i.e. lipid [Ref: Guyton 11/e, p 20, 21; Chatterjee Shinde 6/e, p 6, 71There are two kinds of endoplasmic reticulum :Rough or granular ER or ergastoplasmThey are coated with ribosomesFunction of rough ERprotein synthesisSmooth or agranular ERThey do not have attached ribosomesFunctions of smooth ERlipid synthesismodification and transport of protein synthesized in rough ERprovides the enzymes that control glycogen breakdown when glycogen is to be used for energyprovides a vast number of enzymes that are capable of detoxifying substances, such as drugs, that might damage the cell