Caffeine is a stimulant that acts upon the central nervous system (CNS) so that cells respond better to signals. This molecule is the most common CNS stimulant. The substance is used for its refreshing effect against fatigue. It is an organic molecule
Caffeine belongs to a group of substances called alkaloids. Alkaloids are found naturally in several plant species, such as coffee, tea, and cocoa.
Figure 1: Molecular structure of caffeine