Caffeine is an alkaloid (C8H10O2N4 ) found in coffee, tea, and most soda drinks. Caffeine is also found in some plants. It literally grows on trees, bushes, and some forms of cacti. Over 100 types of plants produce caffeine molecules in their seeds, bark, or other structures.
Caffeine increases the blood pressure and stimulates the central nervous system. It stimulates because caffeine is very similar chemically to adenosine, a substance that functions as a kind of "thermostat" for the brain and keeps neuronal activity within safe limits. It slows down brain activity to a safe level. When caffeine enters the system, it blocks adenosine from binding with its proper receptors. This prevents the brain from being able to slow down. However, caffeine cant stimulate anything by itself, because it is an indirect stimulant. Instead of increasing brain activity itself, caffeine clears the way for the brains own stimulants by preventing adenosine from slowing them down. Therefore, you can only get wired to the extent that your natural stimulants support it. This is why you cant really "overdose" on caffeine. Even though adenosine is inactive, there are other substances that will still function to slow the brain down. Without any other direct stimulants, overall brain activity wont increase to the level that would occur with other drugs such as cocaine or amphetamine.
Caffeine doesnt necessarily work the way most people think it does. Ingesting more caffeine doesnt necessarily cause greater stimulation. The relationship between increasing the dose and the increasing stimulation applies only when the caffeine dose is equal to about 1 - 4 cups of coffee. After that, it probably wont increase brain activity, and it may even have a reverse effect because of caffeines effects on other molecules.
Caffeine is thought to be a relatively safe drug. The only known deaths from caffeine have been accidents. One of these was an adult patient that was killed when a nurse injected 3,200 milligrams of caffeine into him because she thought it contained another drug. This is the lowest dose of caffeine ever known to kill an adult. If taken by mouth, a fatal dose would have to be at least 5,000 milligrams, which is about equal to 40 cups of strong coffee consumed very quickly. Since vomiting would induce long before the fatal amount would be reached, it would be very difficult for even a very determined person to die from an overdose of caffeine. In the few people that have died from caffeine, the actual cause of death was not overstimulation of the brain, but cardiac arrest caused by uncontrolled firing of the nerves that regulate heartbeat.
However, too much caffeine can be dangerous to a persons health. If more than about six average cups of coffee a day are consumed, it could be harmful because people can get addicted. People who have become addicted to caffeine sometimes experience withdrawal headaches and other symptoms when they stop consuming it. These are some of the effects caffeine has on the human body.
A mole is not only an animal but a conversion unit in chemistry. It describes the atomic mass of an element, the formula mass of an ionic compound, or the molecular mass of a molecular compound. A mole also represents a number, as a unit. It represents 6.02 x 1023 atoms, formula units, or molecules.