Caffeine is an example of a(n) _______ because it binds to a receptor that recognizes adenosine but does not elicit the same cellular response as adenosine.
A) ligand
B) agonist
C) antagonist
D) signal molecule
E) hormone

Question

Quizplus · Accepted Answer

Caffeine is an antagonist because it blocks the receptor for adenosine, preventing it from eliciting its normal response. Adenosine acts as a neuromodulator in the brain, and when it binds to its receptors, it slows down cellular activity, making us feel sleepy. By blocking this receptor, caffeine has the opposite effect, increasing cellular activity and making us more alert.

Caffeine Is an Example of A(n) _______ Because It Binds