As can be seen above, caffeine consists of two carbon/nitrogen rings with oxygen and methyl groups as substituents. The fused rings are similar to those in adenine only the substituents differ. Caffeine is found in coffee, tea, and many soft drinks. There is also some amount of caffeine in chocolate, as well as a closely related stimulant, theobromine. The caffeine in sodas is generally produced from the cola berries, and is either a by-product of the cola flavoring or is added for flavor and stimulant effect. There are four ways in which caffeine stimulates the nervous system. Of these, one is of primary improtance. Another has some level of importance, and the other two only occur at unrealistically high levels of caffeine in the body. The first of these methods, and the most important, is blocking adenosine receptors. As caffeine has a similar structure to the adenosine group, but also has more heavily electrophilic and nucleophilic functional groups than adenosine as, for instance, seen in cyclic AMP. This means that caffeine will fit adenosine receptors as well as adenosine itself will. Thus, cyclic AMP remains active, rather than being broken down. Second among the effects of caffeine is phosphodiesterase inhibition. The phosphodiesterase class of enzymes includes a number of enzymes responsible for breaking down cyclic AMP, thus depriving the body of an energy supply. Caffeine fools phosphodiesterase into attacking it instead, which inhibits the breakdown of cyclic AMP. However, the concentration of caffeine required for this effect to become significant is sufficiently high that the adenosine blocking remains the dominant factor. The other two laboratory effects of caffeine have been judged insignificant in actual biochemical situations. Caffeine can increase the speed of rapid information processing by 10% 1, and a cup of regular (caffeine-containing) coffee after lunch helps to counteract the normal post-lunch dip' in ability to sustain... [continues]
Cite This Essay
(1999, 10). Caffeine 2. StudyMode.com. Retrieved 10, 1999, from http://www.studymode.com/essays/Caffeine-2-10815.html
"Caffeine 2" StudyMode.com. 10 1999. 10 1999 <http://www.studymode.com/essays/Caffeine-2-10815.html>.
"Caffeine 2." StudyMode.com. 10, 1999. Accessed 10, 1999. http://www.studymode.com/essays/Caffeine-2-10815.html.