Caffeine is the most widely used stimulant in the world today. This naturally produced molecule is found in popular beverages from coffee to black tea to Coca Cola. Although humans use caffeine to ward off drowsiness, the caffeine produced by plants makes the leaves and seeds less desirable to insects. In humans caffeine stimulates the central nervous system, increasing levels of neurotransmission resulting in increased alertness. Beginning with the discovery of tea in 3000 BCE, the natural boost given by caffeine has resulted in a long and rich history of caffeinated substances around the globe.

On the structure of caffeine below, identify the functional groups that are present by dragging the functional group name listed below onto the appropriate target boxes on the structure.

methyl hydroxy lamino carboxyl aldehyde phosphate sulfhydryl phenyl none