In this module, we learned about G protein function as a binary switch. G proteins have an intrinsic enzymatic ability to hydrolyze GTP to GDP + Pi. Why, then, would a cell need additional G protein...

In this module, we learned about G protein function as a binary switch.  G proteins have an intrinsic enzymatic ability to hydrolyze GTP to GDP + Pi.  Why, then, would a cell need additional G protein controls like GEFs or GAPs?  What advantages do you see this providing?