MEDICAL PHYSIOLOGY

Detailed explanation-1: -G protein-coupled receptor (GPCR), also called seven-transmembrane receptor or heptahelical receptor, protein located in the cell membrane that binds extracellular substances and transmits signals from these substances to an intracellular molecule called a G protein (guanine nucleotide-binding protein).

Detailed explanation-2: -G protein-coupled receptors are found only in eukaryotes, including yeast, choanoflagellates, and animals. The ligands that bind and activate these receptors include light-sensitive compounds, odors, pheromones, hormones, and neurotransmitters, and vary in size from small molecules to peptides to large proteins.

Detailed explanation-3: -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-4: -Explanation: Rhodopsin is a very stable G-protein coupled receptor.

Detailed explanation-5: -GPCRs are the largest family of membrane proteins and mediate most cellular responses to hormones and neurotransmitters, as well as being responsible for vision, olfaction and taste.