AP BIOLOGY

Detailed explanation-1: -The classical view of heterotrimeric G protein signaling places G proteins at the cytoplasmic surface of the cell’s plasma membrane where they are activated by an appropriate G protein-coupled receptor.

Detailed explanation-2: -G protein-coupled receptors (GPCRs) are integral membrane proteins that reside in the plasma membrane of eukaryotic cells. They are central to transmitting signals from the extracellular milieu to the inside of the cell.

Detailed explanation-3: -At the plasma-membrane, these proteins function as molecular switches that initiate and regulate multiple signal transduction pathways. Their fundamental role is in coupling external stimuli with cytoplasmic and nuclear targets, and their activation depends on their association with growth factor receptors.

Detailed explanation-4: -G protein-coupled receptors (GPCRs) are seven-transmembrane proteins that are located in the cell membrane, with their N-and C-termini located on the outer and inner surfaces, respectively. GPCRs mediate various cellular responses from the extracellular environment.