The family of GPCRs that sense bitter compounds is much larger and more disparate in amino acid sequence than those that sense sweet or umami. Why might this be adaptive?
A) Bitter receptors do not have to be as sensitive as those for sweet or umami. B) The ability to distinguish between many bitter compounds allows the animal to eat the one most agreeable to its digestive system. C) Bitter compounds are usually toxic, and so the ability to sense a wide variety of them is protective. D) Bitter compounds usually contain dense calories, which help a species survive and thrive.