<prompt> Endoplasmic reticulum do not paicipate inProtein synthesisMuscle contractionProtein soingGlycoproteins  <response>: Rough Endoplasmic Reticulum is involved in protein synthesis. EPR also involved in glycosylation of N linked glycoproteins. Exocytic pathway of protein soing is done by both RER GA Golgi apparatus Reference: Harper; 30th edition 