Briefly explain why larger molecular weight proteins are located at the top of the gel. Shown below is an example of 2D gel data from your textbook (Figure B-16). Why are some “spots” larger or smaller than others? You work in a mouse lab. You make two separate proteins extracts from brain and liver, followed by analysis of the proteins by 2D gel electrophoresis. Do you expect the two gel images to be the same or different Explain your answer.