Final answer:
The amino terminus of a G-protein coupled receptor is on the extracellular side, while the carboxyl terminus is on the cytoplasmic side of the cell.
Step-by-step explanation:
The G-protein coupled receptors (GPCRs) are integral membrane proteins that facilitate cellular communication. They have specific regions, with the amino terminus (N-terminus) being the part of the protein that has a free amino group. This N-terminus is located on the extracellular side of the cell membrane. Conversely, the carboxyl terminus (C-terminus) is the part of the protein with a free carboxyl group, and it is located on the cytoplasmic side of the cell. In context, when a GPCR binds to its ligand, it activates a nearby G-protein on the cytoplasmic side, influencing cellular responses and signaling pathways.