True about G-protein receptor complex

G protein-coupled receptors (GPCRs) which are also known as seven-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptor, and G protein-linked receptors (GPLR), constitute a large protein family of receptors, that sense molecules outside the cell and activate inside signal transduction pathways and, ultimately, cellular responses.Coupling with G proteins, they are called seven-transmembrane receptors because they pass through the cell membrane seven times.