Which of the following statements about a G protein signalling pathway is true?
A) A G protein-coupled receptor bound to GTP is in its active state.
B) A G protein bound to GTP is in its active state.
C) A G protein bound to GDP is in its active state.
D) Hydrolysis of bound GTP by a G protein activates the G protein.

Question

Quizplus · Accepted Answer

When a G protein is bound to GTP, it is in its active state, allowing it to interact with downstream effector molecules and initiate a signalling cascade. Hydrolysis of bound GTP by the G protein results in its inactivation. The G protein-coupled receptor itself may also be active or inactive depending on its ligand binding and subsequent conformational changes, but this is distinct from the activation state of the G protein itself.

Which of the Following Statements About a G Protein Signalling