This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biological Function of Proteins, Subject name: Biochemistry
Rough endoplasmic reticulum is site of synthesis for 
Select and explain. 
A. Protein, B. Cholesterol, C. Carbohydrate, D. Fat
A: Protein
Answer: A: Protein 
Explanation: Ans. is 'a' i.e. Protein Rough endoplasmic reticulum is concerned withProtein synthesis*Initial folding of the polypeptide chains with the formation of disulfide bondsSmooth endoplasmic reticulum is concerned withSteroid synthesis*Detoxification processesAs sarcoplasmic reticulum plays important role in skeletal and cardiac muscle contraction *