Caffeine


 * Caffeine A Mini-Report by Tu Anh Le **

__Name and Structure of Caffeine __ 

How did caffeine get its name? The word "caffeine" came from the German word //kaffee// and the French word //café//, each meaning coffee. The medical name of caffeine, based on its molecular structure, is 1,3,7-trimethylxanthine. It's chemical formula is C8H10N4O2. The German chemist Emil Fischer (1852-1919) was the first to work out the molecular structure of caffeine during the 1890s. He first synthesized caffeine from basic raw materials in 1895. Two years later, he was certain that he finally discovered the structural formula of caffiene.

Caffeine is an alkaloid, a class of naturally occurring compounds containing nitrogen and having the properties of an organic amine base. That is why in its pure form, caffeine is an intensely bitter and white powder. It is odorless and is composed of long hexagonal prisms.



 __How is Caffeine Made? __ 

Caffeine is a drug naturally found in certain leaves, seeds, and fruits of over 60 plants worldwide. Some of these sources are coffee beans, guarana, yerba maté, kola nuts, cacao beans, and tea, with guarana paste (from the Paullinia tree) having the highest concentration of caffeine at 4%. Did you know that caffeine acts as a natural pesticide used to paralyze and kill insects that attempt to eat the plant?

Caffeine is also made in labs and can also be isolated from its natural source by manufacturers and added to energy drinks as an additive or as an ingredient in certain drug products, such as cold and headache remedies.

The first to isolate caffeine, from Arabian mocha beans, was the German chemist Friedrich Ferdinand Runge in 1819. During the 1820's, scientists identified the stimulating agents in coffee, tea, and chocolate. But they did not realize they had discovered the same ingredient: caffeine! In 1840, two reasearchers named T. Martins and D. Berthemot, working independently showed that all of these active agents were chemically identical to caffeine isolated from coffee beans.

Caffeine can be directly isolated from tea leaves. Caffiene does not exist alone in the tea leaves. It is accompanied by other natural substances from which it must be seperated. Caffiene constitutes only as much as 5% of the weight in leaves and and is water soluble. The main problem here is that Tannins, a derivative of Catechin and Flavonoids, are also water soluble. Fortunately, caffeine is soluble in non-polar organic solvents while tannins are not. Therefore, the isolation of caffeine from tea leaves can be carried-out in the following steps:

 A more detailed laboratory experiment on the **Isolation of Caffeine from Tea Leaves** can be found [|here.]
 * 1) Extract the Caffiene and Tannins into the hot water.
 * 2) Extract the caffiene into a non-polar organic solvent; Methylene Chloride.
 * 3) Dry the Mthylene Chloride of any remaining water.
 * 4) Evaporate the Methylene Chloride, leaving impure Caffeine.
 * 5) Purify the Caffeine by sublimation.

 __How Does Caffeine Affect Us? __ 

Caffeine is quickly and completely removed from the brain. Its effects are short-lived and it tends not to negatively affect concentration or higher brain functions. Yet still, a large majority of us consume considerable amounts of caffeine, either through coffee, tea, energy drinks, or over-the-counter drugs, on a day-to-day basis in order to stay alert and awake. A normal dose of caffeine is generally considered to be 100mg (about half cup of coffee). A low to moderate intake is 130 to 300mg of caffeine a day, while heavy consumption means intaking more than 6 000 mg/day. The lethal dose of caffiene is between 13 to 19 grams. That would be like drinking around 100 cups of coffee in one sitting!

On the wary side, consuming as little as 100 mg of caffeine a day may cause the person to become dependent on it. They may develop withdrawal symptoms such as tiredness, irritability, and headaches, if he/she quits caffeine suddenly. So that's the reason why Mom gets so cranky when she doesn't get her coffee!

Caffeine sensitivity (amount of caffeine required to cause an effect in a person) depends on the person. Generally, the smaller the person, the less caffeine needed. People who regularly take in a lot of caffeine soon develop less sensitivity to it. This means that they may require more caffeine to achieve the same effects.

It is important to know that caffeine is an addictive drug. Among its many actions, it operates using the same mechanisms that amphetamines, cocaine, and heroin use to stimulate the brain. Caffeine increases dopamine levels in the same way that amphetamines do. Dopamine is a neurotransmitter that, in certain parts of the brain, activates the pleasure center. In comparison, caffeine's effects are milder than amphetamines, cocaine and heroin, but it is manipulating the same channels in the brain, and that is one of the things that gives caffeine its addictive qualities.

Caffeine is also a diuretic, meaning that it can cause person to urinate more. This may cause dehydration if large caffeine consumption is taken alongside hot weather, during long workouts, or in situations where copious amounts of sweating is required.

Caffeine can also cause the body to lose calcium, leading to bone loss over time. Drinking caffeine-containg soft drinks instead of milk can have an even greater impact on bone density and can greater the risk of osteoporosis development. Children, teens, and pregnant women should try to limit their caffeine consumption as much as possible. These stages in life require the important growth and development of bones so it is wise to stay away!

<span style="color: #1cb575; font-family: Georgia,serif; font-size: 144%;">__How Does Caffeine Keep Us Awake?__ <span style="font-family: Georgia,serif;"> Caffeine works by changing the chemistry of the brain by blocking the action of adenosine (a natural brain chemical), the chemical associated with sleep.

Adenosine sends signals that the brain needs to rest. "Since adenosine secretion reflects brain cell activity, rising concentrations of this chemical may be how the organ gauges that it has been burning up its energy reserves and needs to shut down for a while." (Source: [|ScienceNewsOnline: Napless cats awaken interest in adenosine]) Adenosine is produced through daily activities. Your muscles create adenosine as a byproduct of exercise.

The chemical adenosine binds to the adenosine receptors in the brain. This binding of adenosine causes drowsiness by slowing down nerve cell activity. This also causes blood vessals to dilate in the brain (possibly to let more oxygen in during sleep).

To a nerve cell, caffeine looks like adenosine. Therefore, when you consume caffeine, it binds to the adenosine receptors. The cells cannot sense adenosine anymore because caffeine is taking up all the receptors adenosine binds to. So, instead of slowing down, the cells speed up. You can see that caffeine also causes the brain's blood vessals to constrict because it blocks adenosine's ability to open them up. That's why some headache medicines contain caffeine (like Anacin)-- if you have a vascular headache, the caffeine will close down the blood vessals and relieve it.

With caffeine blocking adenosine, neuron firing in the brain is increased. The pituitary gland sees all of the activity and assumes that some sort of emergency must be occuring. It releases hormones that tell the adrenal glands to produce adrenaline (epinephrine). Adrenaline is, of course, the "fight-or-flight" hormone and has a number of effects on your body.

<span style="color: #000000; font-family: Georgia,serif;">For all of you that have been wondering all this time, this explains why we are generally more alert when we ingest a fair amount of caffeine.
 * <span style="font-family: Georgia,serif;">Your pupils dilate
 * <span style="font-family: Georgia,serif;">Your breathing tubes open up (that's why some people suffering from severe asthma attacks are sometimes injected with epinephrine)
 * <span style="font-family: Georgia,serif;">Your heart beats faster
 * <span style="font-family: Georgia,serif;">Blood vessals on the surface contrict to slow blood flow from cuts and also to increase blood flow to muscles; blood pressure rises
 * <span style="font-family: Georgia,serif;">Blood flow to the stomach slows
 * <span style="font-family: Georgia,serif;">The liver releases sugar into the bloodstream for extra energy
 * <span style="font-family: Georgia,serif;">Muscles tighten up ready for action
 * sigh* All those energy drinks for those all-nighters...



<span style="color: #1cb575; font-family: Georgia,serif; font-size: 144%;"> __Another Interesting Fact - Caffeine and Teens: Where Are They Getting All The Caffeine From?__ <span style="color: #1cb575; font-family: Georgia,serif; font-size: 120%;">

<span style="color: #000000; font-family: Georgia,serif;">It has been addressed by British Columbia's Ministry of Education that school should be more aware of caffeine consumption in teens.

Caffeine will cause the same effects in children and teens as they do in adults but because their smaller size and hormonal changes, too much caffeine may be harder on them. Students get their caffeine in soft drinks, coffee, tea, iced mocha drinks, and other sweet energy drinks such as Monster, Red Bull, and RockStar. Occassionally, the amount of caffeine isn't listed on the label but looking through the ingredient list for natural sources can tell you whether it contains caffeine or not (list of natural sources in section How is Caffeine Made). The //Guidelines for Food and Beverage Sales in BC Schools// say that schools should only offer choices with less than 15 mg.

Health Canada recommends:

<span style="font-family: Georgia,serif;">
 * <span style="font-family: Georgia,serif;">7 - 9 years old: 62.5 mg per day
 * <span style="font-family: Georgia,serif;">10 - 12 years old: 85 mg per day
 * <span style="font-family: Georgia,serif;">Teens: 2 mg/kg of body weight per day

The list (from two different sources) below mentions popular brands and drinks that teens consume on a day-to-day basis. <span style="font-family: Georgia,serif;"> Source: U.S. Food and Drug Administration, National Soft Drink Association, Center for Science in the Public Interest. <http://kidshealth.org/teen/food_fitness/nutrition/caffeine.html#>
 * <span style="font-family: Georgia,serif;">**Drink/Food/Supplement** || <span style="font-family: Georgia,serif;">**Amt. of Drink/Food** || <span style="font-family: Georgia,serif;">**Amt. of Caffeine** ||
 * <span style="font-family: Georgia,serif;">SoBe No Fear || <span style="font-family: Georgia,serif;">8 ounces || <span style="font-family: Georgia,serif;">83 mg ||
 * <span style="font-family: Georgia,serif;">Monster energy drink || <span style="font-family: Georgia,serif;">16 ounces || <span style="font-family: Georgia,serif;">160 mg ||
 * <span style="font-family: Georgia,serif;">Rockstar energy drink || <span style="font-family: Georgia,serif;">8 ounces || <span style="font-family: Georgia,serif;">80 mg ||
 * <span style="font-family: Georgia,serif;">Red Bull energy drink || <span style="font-family: Georgia,serif;">8.3 ounces || <span style="font-family: Georgia,serif;">80 mg ||
 * <span style="font-family: Georgia,serif;">Jolt cola || <span style="font-family: Georgia,serif;">12 ounces || <span style="font-family: Georgia,serif;">72 mg ||
 * <span style="font-family: Georgia,serif;">Mountain Dew || <span style="font-family: Georgia,serif;">12 ounces || <span style="font-family: Georgia,serif;">55 mg ||
 * <span style="font-family: Georgia,serif;">Coca-Cola || <span style="font-family: Georgia,serif;">12 ounces || <span style="font-family: Georgia,serif;">34 mg ||
 * <span style="font-family: Georgia,serif;">Diet Coke || <span style="font-family: Georgia,serif;">12 ounces || <span style="font-family: Georgia,serif;">45 mg ||
 * <span style="font-family: Georgia,serif;">Pepsi || <span style="font-family: Georgia,serif;">12 ounces || <span style="font-family: Georgia,serif;">38 mg ||
 * <span style="font-family: Georgia,serif;">7-Up || <span style="font-family: Georgia,serif;">12 ounces || <span style="font-family: Georgia,serif;">0 mg ||
 * <span style="font-family: Georgia,serif;">Brewed coffee (drip method) || <span style="font-family: Georgia,serif;">5 ounces || <span style="font-family: Georgia,serif;">115 mg* ||
 * <span style="font-family: Georgia,serif;">Iced tea || <span style="font-family: Georgia,serif;">12 ounces || <span style="font-family: Georgia,serif;">70 mg* ||
 * <span style="font-family: Georgia,serif;">Cocoa beverage || <span style="font-family: Georgia,serif;">5 ounces || <span style="font-family: Georgia,serif;">4 mg* ||
 * <span style="font-family: Georgia,serif;">Chocolate milk beverage || <span style="font-family: Georgia,serif;">8 ounces || <span style="font-family: Georgia,serif;">5 mg* ||
 * <span style="font-family: Georgia,serif;">Dark chocolate || <span style="font-family: Georgia,serif;">1 ounce || <span style="font-family: Georgia,serif;">20 mg* ||
 * <span style="font-family: Georgia,serif;">Milk chocolate || <span style="font-family: Georgia,serif;">1 ounce || <span style="font-family: Georgia,serif;">6 mg* ||
 * <span style="font-family: Georgia,serif;">Jolt gum || <span style="font-family: Georgia,serif;">1 stick || <span style="font-family: Georgia,serif;">33 mg ||
 * <span style="font-family: Georgia,serif;">Cold relief medication || <span style="font-family: Georgia,serif;">1 tablet || <span style="font-family: Georgia,serif;">30 mg* ||
 * <span style="font-family: Georgia,serif;">Vivarin || <span style="font-family: Georgia,serif;">1 tablet || <span style="font-family: Georgia,serif;">200 mg ||
 * <span style="font-family: Georgia,serif;">Excedrin extra strength || <span style="font-family: Georgia,serif;">2 tablets || <span style="font-family: Georgia,serif;">130 mg ||
 * <span style="font-family: Georgia,serif;">*denotes average amount of caffeine ||

What should our schools do then?The most important thing to do is to offer healthy and affordable ($3 for a juice box is **not** affordable!) beverage and food choices to aid in the development of children and teens and their healthy choices for the future.

<span style="font-family: Georgia,serif;"> <span style="color: #1cb575; font-family: Georgia,serif; font-size: 130%;">__Bibliography__ <span style="font-family: Georgia,serif; font-size: 80%;"> Brain, Marshall, and Charles W. Bryant. "How Caffeine Works." //HowStuffWorks//. 01 Apr 2000. Web. 4 Jun 2010. <http://health.howstuffworks.com/caffeine.htm>.

Kovacs, Betty. "Caffeine Health Effects, Facts, Statistics, Addiction and Withdrawal ." //MedicineNet//. MedicineNet, Inc., n.d. Web. 4 Jun 2010. <http://www.medicinenet.com/caffeine/article.htm>.

Helmenstine, Anne Marie. "Caffeine Chemistry." //About.com Guide//. N.p., n.d. Web. 4 Jun 2010. <http://chemistry.about.com/od/moleculescompounds/a/caffeine.htm>.

BookRags Staff. "Caffeine." //BookRags//. N.p., 2005. Web. 4 Jun 2010. <http://www.bookrags.com/research/caffeine-woc/>.

CHEM 333L, Organic Chemistry Laboratory. "Isolation of Caffeine from Tea." 1.1. 2-4. Web. 5 Jun 2010. <http://infohost.nmt.edu/~jaltig/Caffeine.pdf>.

Gavin, Mary L., and Jessica Donze Black. "Caffeine." //Teens Health//. The Nemours Foundation, Jan 2008. Web. 5 Jun 2010. <http://kidshealth.org/teen/food_fitness/nutrition/caffeine.html#>.

"Why does caffeine keep you awake?." 21 January 2009. //HowStuffWorks//. HowStuffWorks.com. <http://health.howstuffworks.com/caffeine-awake.htm> 04 June 2010.

Brain, Marshall. "How Sleep Works." 01 April 2000. //HowStuffWorks.// HowStuffWorks.com. <http://health.howstuffworks.com/sleep.htm> 04 June 2010.

Travis, J. "Napless Cats Awaken Interest in Adenosine." //Science News Online//. Science Service, 24 May 1997. Web. 4 Jun 2010. <http://www.sciencenews.org/sn_arc97/5_24_97/fob2.htm>.

BC Community Nutritionists Council, School Food Advisory Comimitee. "Caffeine and the Student Body." //ActNowBC// 1. Web. 5 Jun 2010. <http://www.bced.gov.bc.ca/health/caffeine.pdf>.

"Caffeine Chemical Structure." //About.com: Chemistry//. Web. 4 Jun 2010. <http://chemistry.about.com/od/factsstructures/ig/Chemical-Structures---C/Caffeine-Chemical-Structure.htm>.

"Guarana Plant Caffeine." //EthnoPlants//. Web. 4 Jun 2010. <http://www.ethnoplants.com/catalog/images/Guarana_plant_caffeine.jpg>.

"Friedlieb Ferdinand Runge." //About.com: Friedlieb Ferdinand Runge//. Web. 4 Jun 2010. <http://z.about.com/d/chemistry/1/G/I/3/1/Friedlieb_Ferdinand_Runge.jpg>.

"Tea Steeping." //Steepology//. Web. 4 Jun 2010. <http://www.steepology.com/wp-content/uploads/2007/03/414953998_2caeea1e7d.jpg>.

"Energy Drinks." //Jaskt Files//. Web. 4 Jun 2010. <http://jakst.files.wordpress.com/2009/02/energy-drinks.jpg>.

"Adenosine." //Biology @ Davidson//. Web. 4 Jun 2010. <http://www.bio.davidson.edu/courses/Immunology/Students/spring2000/lee/restricted/adenosine.gif>.

<span style="font-family: Georgia,serif; font-size: 80%;">"Osteoporosis." //ChrisChamCL's WebBlog//. Web. 4 Jun 2010. <http://chrischamcl.files.wordpress.com/2009/10/osteoporosis.jpg>.

"The Caffeine Curve ." //Coffee, Tea, and Me. Web. 5 Jun 2010. <http://coffeeteablog.com/wp-content/uploads/caffeine-curve.jpg>. //

"Pure Caffeine Powder." //Euro-Caffeine//. Web. 5 Jun 2010. <http://www.euro-caffeine.com/images/pure%20powder%20copy.jpg>.

"Coffee Cup." //HealthSkills//. Web. 5 Jun 2010. <http://healthskills.files.wordpress.com/2008/09/coffee-cup.jpg>.

"All-Nighter." //Unofficial Standford Blog//. Web. 5 Jun 2010. <http://tusb.stanford.edu/all-nighter.jpg>.

"Kidsbucks." //Babble//. Web. 5 Jun 2010. <http://babble.com/CS/blogs/strollerderby/2007/09/08-15/Kidsbucks.jpg>.