Final answer:
A single G-protein coupled receptor can activate multiple trimeric G-proteins is true, as GPCRs activate associated G-proteins that consist of three subunits, leading to multiple possible cellular responses.
Step-by-step explanation:
A single G-protein coupled receptor can indeed activate multiple trimeric G-proteins, so the answer to the student's question is True. G-protein-coupled receptors (GPCRs) are able to bind to a ligand, undergo a conformational change, and subsequently activate an associated G-protein. The activated G-protein consists of three subunits: α, β, and γ. The binding of a signaling molecule to the GPCR leads to the exchange of GDP for GTP on the α subunit, which then allows the β and γ subunits to dissociate from the α subunit.
Once activated, the G-protein subunits can then trigger different cellular responses. These can involve either the α subunit alone or the dissociated βγ pair, which may in turn activate or interact with other proteins within the cell membrane. Ultimately, the GTP on the α subunit is hydrolyzed back to GDP, and the inactive G-protein reassembles, ready to start the cycle again.