Recent technological advances have led to an explosion of protein structures being determined. But proteins are not static structures and must move and change conformations over a large variety of time and length scales. Computer simulations provide a mechanism to understand this motion and determine how conformational changes can yield the function of a given protein. In this talk I will describe how we have used simulations to understand the function of a variety of membrane proteins including ion channels that sense mechanical and electrical forces. In addition, I will give examples of how we can use these techniques to aid in the rational design of drugs and the mechanistic understanding of inherited diseases.