( 1 ) rough endoplasmic reticulum , from which ribosomes had been removed by treatment with pyrophosphate and citrate , bound over 50 % of added polyribosomes , whereas the untreated ( or control ) rough and smooth endoplasmic reticulum and the smooth endoplasmic reticulum treated with pyrophosphate-citrate did not bind polyribosomes .
C0230779
rough endoplasmic reticulum
C0035553
ribosomes