<- Paul Berg's Protein synthesis: an epic at the cellular level Chances are if you took a biology class where you learned about the cell, you saw this video when you went over protein synthesis at the ribosomal level. In the beginning of the video Paul Berg provides a very brief overview of how it all works and how it will appear in the interpretive dance. When my professor showed it to the class he pointed out a couple of things that researchers discovered since the making of the video. I've been trying to figure out what they are because I didn't write it in my notes and it's been driving me crazy. I noticed there's no mention of A P and E sites? In the video Berg only shows the tRNAs going in and then out of the ribosome and peptidyl-aminosyntase on the large subunit. Beyond that I can't really figure anything out. Any help would be great!