1. Joyce Jiang Hour: 2

2. Problem The purpose of this experiment is to prove that people do indeed develop a resistance to caffeine if consumed over long periods of time.

3. Hypothesis If two groups of three fifty-year-olds and three twenty- year-olds both drink 24 oz of black coffee, then the difference between the twenty-year-olds’ before and after heart rates will be greater because they do not have as much tolerance to caffeine.

4. Research Caffeine, as stimulant that increases blood pressure and heart rate, is found in over 60 plants. Humans have consumed some form of it ever since the Stone Age. Caffeine blocks adenosine receptors to the brain; reduced adenosine results in more neurotransmitter dopamine, which is why caffeine increases alertness and concentration. However, those effects are only temporary, and when one tries to quit, one may experience side-effects such as anxiety, loss of energy, headaches, and more.

5. Coffea Canaphora. Produces coffee beans from its fruits. Fruits from the guarana plant. Tea Leaves also contain caffeine Yerba mate tree.

6. Procedure Materials: 1. Six 24 oz cups of Folgers Classic Roast “Red Can” coffee (there is about 70-80 mill per 8 oz) 2. Clock/watch 3. Three twenty-year-olds 4. Three fifty-year-olds Procedure: 1. Have three twenty-year-olds put two fingers to their pulse and count the beats for one minute. Repeat. 2. Average both rates. 3. Have three twenty-year-olds drink 24 oz of Folgers coffee each, within ten minutes. 4. Wait forty minutes. 5. Have all three hold two fingers to their pulse and count the number of beats in one minute. Repeat. 6. Average both rates. 7. Record and then average results. 8. Repeat steps 1-7, only this time with three fifty-year-olds

7. Graph