52. e. primarily in the endoplasmic reticulum. RNA is synthesized in the nucleus and it is then transported to cytoplasm where translation or protein synthesis takes place in the rough endoplasmic reticulum where ribosomes are embedded. Solution 52. e. primarily in the endoplasmic reticulum. RNA is synthesized in the nucleus and it is then transported to cytoplasm where translation or protein synthesis takes place in the rough endoplasmic reticulum where ribosomes are embedded..