Charles is an engineer who is evaluating a prototype of an artificial heart. the prototype beats in a synchronized fashion, is hollow, and had tubes attached to it. it can be powered by electrical signals from the brain when it is interfaced with the appropriate nerves. what important feature should charles notice the prototype is missing ?

The small molecule cyclic amp (camp) takes about 0.2 second to diffuse 10 μm, on average, in a cell. suppose that camp is produced near the plasma membrane on one end of the cell; how long will it take for this camp to diffuse through the cytosol and reach the opposite end of a very large cell, on average? assume that the cell is 200 μm in diameter.