<prompt> Rough endoplasmic reticulum is site of synthesis forProteinCholesterolCarbohydrateFat  <response>: Ans. is a i.e. Protein Rough endoplasmic reticulum is concerned withProtein synthesisInitial folding of the polypeptide chains with the formation of disulfide bondsSmooth endoplasmic reticulum is concerned withSteroid synthesisDetoxification processesAs sarcoplasmic reticulum plays important role in skeletal and cardiac muscle contraction 