Question

Place the events below in the correct order.

1) G protein binds to activated receptor forming a receptor-G protein complex
2) Release of GDP by the G protein
3) Change in conformation of the cytoplasmic loops of the receptor
4) Binding of GTP by the G protein
5) Increase in the affinity of the receptor for a G protein on the cytoplasmic surface of the membrane.
6) Binding of a hormone or neurotransmitter to a G-protein coupled receptor
7) Conformational shift in the a subunit of the G protein
a. 6-3-5-1-2-4-7
b. 3-6-5-1-7-2-4
c. 6-3-5-1-7-2-4
d. 6-7-3-5-1-2-4

Answer 1

The events that occur after a hormone or neurotransmitter binds to a G-protein coupled receptor are sequentially binding, conformational changes, affinity increase, complex formation, GDP release, GTP binding, and conformational shift. The correct order is 6-3-5-1-7-2-4.

Step-by-step explanation:

To place the events below in the correct order related to a G-protein coupled receptor:

1. Binding of a hormone or neurotransmitter to a G-protein coupled receptor.
2. Change in the conformation of the cytoplasmic loops of the receptor.
3. Increase in the affinity of the receptor for a G protein on the cytoplasmic surface of the membrane.
4. G protein binds to activated receptor forming a receptor-G protein complex.
5. Release of GDP by the G protein.
6. Binding of GTP by the G protein.
7. The conformational shift in the subunit of the G protein.

The correct sequence is therefore answer option (c) 6-3-5-1-7-2-4.