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How does aspirin work?

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Introduction

Asthma In America, more than 80 billion aspirin tablets are consumed each year. Aspirin is a trade name for acetyl salicyclic acid and is effective as an analgesic, antipyretic, and anti-inflammatory drug. History Aspirin's predecessors, derivatives of salicylic acids, have been used to treat a variety of conditions for more than 2,500 years. The Greek physician, Hippocrates (400BC), recommended the use of willow bark (a natural source of salicylates) to ease pain during childbirth. This use of salicylates was also advocated by Galen, a second century Roman physician, and mentioned in medical texts of the Middle Ages and Renaissance. In 1757, Reverend Edward Stone conducted the first scientific study of natural sources of salicylates and wrote about the success of willow bark in the cure of fevers and aches. Leroux showed in 1829, that salicin is the active agent in willow and was first extracted by Fontana and Brugnatelli. ...read more.

Middle

In the process, an ethanoyl group is transferred from aspirin to serine, and aspirin in converted to salicylic acid. To confirm this theory the serine residue was replaced by alanine (which does not have an OH group). The cyclooxygenase activity of the modified enzyme was unaffected by aspirin. When serine was replaced by asparagines, however, the modified enzyme did not show cyclooxygenase activity. This suggests that ethanoylation of the enzyme's active site prevents binding of arachidonic acid to its surface so that the enzyme cannot convert arachidonic acid into a prostaglandin. Super Aspirins In 1992, chemists discovered that cyclooxygenase (COX) had two forms COX1 and COX2. COX1 converts arachidonic acid to PGl2 which protects the stomach lining whereas COX2 converts arachidonic acid into PGE2 which causes pain. Aspirin inhibits both forms of cyclooxygenase, relieving pain whilst enabling acidic digestive juice to irritate the stomach. X-ray crystallography has allowed a greater understanding of the structure of cyclooxygenase and the ways aspirin works, leading to the development of COX2 inhibiting drugs such as Meloxicam. ...read more.

Conclusion

However, enzymes in the body, interacting with one of the phenol groups, metabolised the drug so its effects were not long lasting. Adrenaline diol was produced aimed at solving this problem by having one phenol group. However, it was not an effective broncholdilator because the methyl ester group could not participate in hydrogen bonding. Adrenaline triol was synthesised with an OH group replacing the methyl ester. However, this OH group was not bonded directly to the benzene ring and so not metabolised by the body. Adrenaline triol was an effective, long lasting bronchodilator but still increased heart rate. Chemists made one further change replacing the 2-propyl group on the nitrogen with a 2-methylpropyl group creating the compound, Salbutamol. In the development of Salbutamol chemists produced and tested over 100 compounds through organic synthesis. This meant the modification process alone, took two years. Salbutamol is effective for 4 hours but chemists at Glaxo later produced Salmeterol (a bronchodilator effective for 12 hours) through an even more drastic change to the group on the nitrogen in Salbutamol. Both Salbutamol and Salmeterol are effective asthma treatments. ...read more.

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The candidates overall response is reasonably good and they have demonstrated a good understanding of this topic but the purpose of this essay is unclear and is there is some room for improvement. There is no clear introduction to this ...

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Response to the question

The candidates overall response is reasonably good and they have demonstrated a good understanding of this topic but the purpose of this essay is unclear and is there is some room for improvement. There is no clear introduction to this essay, which is a mistake. It is important that you take the time to write an introduction as this sets the tone for the rest of your essay. Your introduction should include a few sentences that introduce your topic and a clear statement of what you plan to discuss so that the purpose of you essay is clear.

Level of analysis

It is evident that the candidate has taken time to research aspirin and how it works, this is important as you want to make sure that you get your facts right. By taking the time to research your topic you show dedication and enthusiasm towards your subject which is always a good thing and the additional information this enables you to discuss can make your essay more interesting to read. That said, it is essential that you state any resources you have used, if you have taken information from a book then you must list the name and author of the book you have used and if you take information form an online source you must a link to that source. This allows the reader to see the steps you have taken to prepare for your essay and providing you have written the information in your own words, it shows that your work is not plagiarised. On a final note, the candidate has failed to write a conclusion which causes the essay to come to abrupt end. You should always a write a conclusion, this is your chance to leave the reader with a good impression of your work. Your conclusion should summarise key points form your essay with reference to why these are relevant as this helps to tie together any loose ends.

Quality of writing

This essay is reasonable well written, the candidate uses appropriate technical terms and there no errors with spelling or grammar. However there are times in which this essay is hard to follow, it feels very much like an amalgamation of different facts rather than a discussion. This can often be avoided if you take the time to think about what you want to say and write out a plan. It can also help to read your work as you write so that you stay on track.


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