Math Is Hard
I've been looking at some explanations and pictorial illustrations of ribosomes in my biology book. Now, they say that ribosomes are the sites of protein synthesis, and I am confused because the ribosomes are situated on the outside of the rough ER, but the newly synthesized proteins seem to just "appear" (in the illustrations) on the inside of the rough ER, where they then get pinched off and sent via vesicles to the Golgi Apparatus or to wherever they are destined. What is really going on here? Are these proteins manufactured on the inside or outside of the rough ER? If they are made outside, how do they get inside?