Using electron flow... in a transistor, once the initial bias is set and ac current is moving, how do the electrons get from the emitter into the collector if the base to collector is reverse biased? I'm sorry for such a basic question. It seems as if all the electrons, as they enter into the base region and fill up holes and need to move out, would run head on into the reverse bias condtion and not be able to move any farther in spite of the power supply's attraction. This has always confused me. They flow easily from emitter to base because of the forward bias. Why then do they flow from the base to the collector with a reverse bias? It seems like they would hit a "wall" and not be able to move.