<prompt> Action of alpha subunit of G-protein is:Binding of agonistConversion of GDP to GTPBreakdown of GTP to GDPInternalization of receptors  <response>: Ans. C Breakdown of GTP to GDPRef: KDT 8the p54Alpha subunit of G protein contains GTPase activity and thus dissociates GTP to form GDP. This result in re-uniting a subunit with b and g subunit 