Refer to Animation: Cell Signaling: Termination of Signaling Pathways. Which of the factors could lead to a prolonged increase in heart rate, even in the absence of an external signal? Select all that apply.
an inability of cyclic AMP to activate protein kinase A
an inability to inactivate protein kinase A
an inability of G protein coupled receptors to bind adrenaline
an inability to convert ATP into cyclic AMP
an inability of a G protein to hydrolyze GTP
