Question

You turn on a light so you can get a glass of water. At the moment the light turns on, the amount of gtp bound to the gα subunit of trimeric g proteins __________.

Answer 1

When a signaling molecule binds to a G-protein-coupled receptor, the Gα subunit of the trimeric G protein exchanges GDP for GTP, which results in its activation and subsequent signaling functions within the cell. This activation is part of a broader cellular response system that is essential for many physiological processes.

Step-by-step explanation:

At the moment the light turns on, the amount of guanosine triphosphate (GTP) bound to the Gα subunit of trimeric G proteins increases. This is because the trimeric G protein is part of a signaling process, initiated when a signaling molecule (such as a photon of light in the case of a visual system) binds to a G-protein-coupled receptor (GPCR). This event prompts the exchange of GDP for GTP on the Gα subunit, triggering the dissociation of the α subunit from the β and γ subunits. The α subunit, now active with GTP bound, may then activate other proteins within the cell, leading to a cellular response. The signal is terminated when the Gα subunit hydrolyzes the bound GTP back to GDP, reassociating with the β and γ subunits, and returning the G protein to its inactive state.