By Gabby Shacknai Millions of Americans use caffeine, the world’s most popular drug, every day to boost their energy. Caffeine can produce heightened brain activity, increase athletic performance, increase the flow of oxygen to the brain and raise your heart rate and ability to concentrate. Although useful, the drug can cause jitters, anxiety and discomfort if higher doses are consumed. Show your class this video from the American Chemical Society , then have them answer the following questions. When caffeine enters the body, what three molecules does it break into? What is the role of Adenosine? What are some of the positive effects of caffeine consumption? What about the negative effects? What is the safest average recommended dose of caffeine for adults? Do you consume caffeine? If so, in what form?