chem help..

[Ken]

these questions are from the DNA topic:

1. Briefly explain how aspirin is able to reduce pain and fever.

2. Illustrate, using aspirin as an example, how biochemists modify the structure of drugs to eliminate undesirable side effects. (perhaps just explain it will do...)

3. Explain why pharmaceutical companies manufacture drugs such as aspirin using chemical reactions, while biotechnological processes are used to produce drugs such as insulin.

Thanks! 

[hailstones]

lol ill try..
1. aspirin (acetyl salicylate??) works by blocking both cyclooexgenase 1 and 2. by blocking the first enzyme it inhibits this sending a message to activate prostaglandins which relay pain messages to the brain and the second because this starts part of the inflammatory response....  i may be totally wrong as my text book isnt here... but pretty much works by blocking the active site of an enzyme so it can no longer does its job i.e to let you know when you're in pain.
2. not so sure on this one..... something about changing the OH group as this causes bleeding in the stomach and replacing it with.... something else.. haha someone else can answer that...
3. no idea but id like to know the answer

:-)

[iamdan08]

2. Biochemists modify drugs to improve their properties for various reasons, including eliminating undesirable effects. Is the case of aspirin, salicylic acid irritated the lining of the mouth and stomach because of its acidic nature. In order to overcome this, salicylic acid was reacted with ethanoic anhydride to form acetysalicylic acid, which didn't convert back (hydrolise) to salicylic acid until it is in the small intestine, thus eliminating the undesirable irritating effects.

[bucket]

3)
I'm not 100 percent sure, but I think it is because insulin is a hormone, meaning it is a protein and i don't think it is possible for proteins to be manufactured perfectly, mainly because of the complexity of their final structure (the 3d tertiary structure), therefore to produce it they have to use a biotechnological pathway.
And yeah, aspirin is just a hydrocarbon. :S

I'm sure someone can give a more detailed explanation but hopefully this should give you the gist of it.

[Mao]

2. Biochemists modify drugs to improve their properties for various reasons, including eliminating undesirable effects. Is the case of aspirin, salicylic acid irritated the lining of the mouth and stomach because of its acidic nature. In order to overcome this, salicylic acid was reacted with ethanoic anhydride to form acetysalicylic acid, which didn't convert back (hydrolise) to salicylic acid until it is in the small intestine, thus eliminating the undesirable irritating effects.

the effect is not so much "eliminated", but the presence of the ester suppresses the acidic properties to make it less irritating.