Question

Match the descriptions to the type of G protein.

Heterotrimeric G proteins
Both small G proteins
Inactive form binds GDP
Activated by dimerized growth factor receptors
Monomeric in both active and inactive forms
Activated by 7TM receptors
Active form dissociates to G and G₀y
Active form binds GTP
a) Heterotrimeric G proteins
b) Both small G proteins
c) Inactive form binds GDP
d) Activated by dimerized growth factor receptors
e) Monomeric in both active and inactive forms
f) Activated by 7TM receptors
g) Active form dissociates to G and G₀y
h) Active form binds GTP

Answer 1

Heterotrimeric G proteins have three subunits and are activated when a signaling molecule binds to a G-protein-coupled receptor, resulting in GDP-GTP exchange and dissociation of the β and γ subunits from the α subunit.

Step-by-step explanation:

Heterotrimeric G proteins have three subunits: α, β, and γ. When a signaling molecule binds to a G-protein-coupled receptor, a GDP molecule associated with the α subunit is exchanged for GTP. The β and γ subunits dissociate from the α subunit, and a cellular response is triggered either by the α subunit or the dissociated βγ pair. Hydrolysis of GTP to GDP terminates the signal.