AP BIOLOGY

Detailed explanation-1: -GPCRs are membrane-bound proteins that have seven membrane-spanning domains connected by intracellular and extracellular domains.

Detailed explanation-2: -G protein-coupled receptors, or GPCRs, also known as 7-Transmembrane receptors (7-TM receptors), are integral membrane proteins that contain seven membrane-spanning helices. As the name suggests they are coupled to heterotrimeric G proteins on the intracellular side of the membrane.

Detailed explanation-3: -The seven transmembrane receptors, also known as G protein coupled receptors, represent the largest of the several families of plasma membrane receptors, comprising more than a thousand genes and regulating virtually all known physiological processes in mammals.

Detailed explanation-4: -All GPCRs share a similar structure, which includes seven transmembrane domains, an extracellular amino terminal, an intracellular carboxyl terminal, three extracellular loops, and three cytosolic loops (Fig.