Caffeine is a crystalline xanthine alkaloid compound, which basically means it is a naturally occurring element.

Extracts from this essay...

Introduction

Caffeine is a crystalline xanthine alkaloid compound, which basically means it is a naturally occurring element. In its pure form, caffeine is a white coloured, bitter tasting substance which acts as a stimulant. It works by speeding up the central nervous system and as a result, leaving the user with and elevated mood, higher levels of concentration, and being less drowsy. It can be found in commercial form in many beverages and foods such as coffee, tea, soft drinks, and chocolate. As well as this it can be bought over the counter in pill form. Due to its abundance it is the worlds most used drug. (2007 centre for addiction and mental health). Caffeine is also often used medically for both drowsiness and in a number of neonatal medicines.

Middle

The prevalence of caffeine is very different over the spectrum of beverages: * An average cup of coffee (200ml) contains approximately 180mg of caffeine. * Decaf coffee of the same volume on contains 2mg of caffeine. * A cup of tea (200ml) contains about 80mg of caffeine. * A bottle of coca cola (360ml) contains 64mg of caffeine. * An average block of chocolate (50g) contains about 20mg of caffeine. Humans have consumed caffeine since the Stone Age (chow p.19 - 20(Czech edition). It is known that the original consumption was by chewing the bark and leaves of certain plants. In humans, there are four types of adenosine receptors. They all have different functions although they all overlap.

Conclusion

The adenosine receptors play an important role in regulation the amount of dopamine produced. Caffeine, when consumed, is believed to work by blocking adenosine receptors in the brain and other organs. The result is the reduced ability to slow down cellular activity. The resulted stimulated nerve cells produce adrenaline, which increases heart rate, increases blood flow to muscles, but decreases blood flow to the skin and organs. The blocked adenosine receptors also allow more production of dopamine which results in an elevated mood along with the usual symptoms of the intake of caffeine. Caffeine, however, only blocks out the first two types of adenosine receptors. A chemical called theophylline has effect on all four types. Theophylline is found in tea in small amounts along with caffeine so, although it is only slight, tea has a broader effect on the body.

The above preview is unformatted text

Found what you're looking for?

  • Start learning 29% faster today
  • Over 150,000 essays available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Over 180,000 student essays
  • Every subject and level covered
  • Thousands of essays marked by teachers
  • Over 180,000 essays
    written by students
  • Annotated by
    experienced teachers
  • Ideas and feedback to write
    your own great essays

Marked by a teacher

This essay has been marked by one of our great teachers. You can read the full teachers notes when you download the essay.

Peer reviewed

This essay has been reviewed by one of our specialist student essay reviewing squad. Read the full review on the essay page.

Peer reviewed

This essay has been reviewed by one of our specialist student essay reviewing squad. Read the full review under the essay preview on this page.