Final answer:
A G-protein is a guanosine triphosphate (GTP) hydrolase that plays a critical role in cell signaling. It is comprised of three subunits: alpha (α), beta (β), and gamma (γ). When a signaling molecule binds to a G-protein-coupled receptor, a GDP molecule associated with the alpha subunit is exchanged for GTP, triggering a cellular response.
Step-by-step explanation:
A G-protein is a guanosine triphosphate (GTP) hydrolase that plays a critical role in cell signaling. It is comprised of three subunits: alpha (α), beta (β), and gamma (γ).
When a signaling molecule binds to a G-protein-coupled receptor in the plasma membrane, a GDP molecule associated with the alpha subunit is exchanged for GTP. This leads to the dissociation of the beta and gamma subunits from the alpha subunit, triggering a cellular response.