Match up the correct receptor type and effect. select one:

a. metabotropic; direct opening of an ion channel

b. ionotropic; more time required to open an ion channel

c. metabotropic; g protein activation leads to activation of a second-messenger

d. metabotropic; rapid opening of a single ion channel

e. metabotropic; rapid short-lived effects on ion channels

I believe the correct match and the answer is C, metabotropic; g protein activation leads to activation of a second messenger. Metabotropic receptors lack opening or closing channels, but instead they are linked to G-protein. When a ligand binds the metabotropic receptor, the receptor activates the G-protein, which in turn activates a second messenger. The second messenger may then, either travel and bind to and open ion channels located on the membrane or the messenger may go and activate other intermediate molecules inside the cell. This varies from one metabotropic receptor to another.