Question

Describe how a cellular response is reached when using G-protein coupled receptor.

Answer 1

Cell signaling using G-protein-linked receptors occurs as a cyclic series of events, where the ligand binds to the receptor and activates the G-protein. The G-protein then activates other proteins in the cell before being deactivated and forming the inactive G-protein. This cycle repeats to reach a cellular response.

Step-by-step explanation:

Cell signaling using G-protein-linked receptors occurs as a cyclic series of events. Before the ligand binds, the inactive G-protein can bind to a newly revealed site on the receptor specific for its binding. Once the G-protein binds to the receptor, the resulting change in shape activates the G-protein, which releases guanosine diposphate (GDP) and picks up guanosine 3-phosphate (GTP).

The subunits of the G-protein then split into the a subunit and the By subunit. One or both of these G-protein fragments may be able to activate other proteins as a result. After awhile, the GTP on the active a subunit of the G-protein is hydrolyzed to GDP and the By subunit is deactivated. The subunits reassociate to form the inactive G-protein and the cycle begins anew.

Answer 2

When a signaling molecule binds to the GPCR, the G protein alpha subunit exchanges GDP for GTP. The alpha subunit dissociates from the beta and gamma subunits and interacts with other molecules, ultimately triggering a cellular response. ... GTP is hydrolyzed to GDP, and the signaling molecule comes off of the receptor.