<prompt> True about G protein-coupled receptors isG proteins bind to hormones on the cell surfaceAll the three subunits alpha, beta and gamma should bind to each other for G protein to actG proteins act as inhibitory and excitatory because of difference in alpha subunitG protein is bound to GTP in resting state  <response>: Heteromeric g protein located inside the cell are activated by g protein coupled receptors that span the cell membrane. Signaling molecules bind to a domain of GPCR out side the cell and an intracellular GPCR domain then in turn activates a paicular G protein Ref:Guyton and Hall textbook of medical physiology 12th edition,page number:540,541,542 