You are a graduate student working with isolated aortic rings in a muscle bath. you measure vessel contraction (force in mn) in response to compounds that are thought to bind to g protein coupled receptors. when you expose aortic rings to drug x alone you get no response. when you expose the aorta to drug y alone the vessel contracts generating a force of 17mn. when you expose the aorta to drugs x and y together the aorta contracts more than with drug y alone and generates a force of 24mn.

where on the receptor does drug x bind?

where on the receptor does drug y bind?

explain why drugs x and y have an additive effect.