Two intracellular molecules X and Y are both normally synthesized at a constant rate of 1000 molecules per second per cell.  Molecules X is broken down slowly:  each molecule of X survives on average for 100 seconds,  Molecule Y is broken down 10 times faster, each molecule of Y survices on average for 10 seconds.  
a.  calculate how many molecules X and Y the cell contains at any time
b.  If the rates of synthesis of both X and Y are suddenly increased tenfold to 10,000 molecules per second per cell without any change in their degradation rates-how many molecules of X and Y will there be after one second?
c.  Which molecule would be preferred for rapid signaling?  Why?
d.  Which molecule would be preferred for slow signaling?  Why?