#6. Caffeine can bind to adenosine receptors in brain cells
Caffeine has a similar molecular structure to adenosine, a neurotransmitter, a substance that transmits nerve impulses in the brain. Because of its chemical resemblance to adenosine, caffeine can bind to adenosine receptors in brain cells. Caffeine’s stimulant effects come mainly from the way it acts on the brain’s adenosine receptors. Normally, the binding of adenosine to its receptors produces drowsiness and depresses the central nervous system, which slows down nerve cell activity and promotes relaxation.