Refer to the biochemistry in focus section of your text for this chapter to answer this question. sarin inhibits acetylcholinesterase by covalently modifying the enzyme active site. pyridostigmine is a competitive inhibitor of acetylcholinesterase and can serve as an antidote for sarin poisoning. how does pyridostigmine prevent sarin from inhibiting acetylcholinesterase? pyridostigmine binds to sarin and prevents it from binding to and modifying the enzyme active site. pyridostigmine reverses the covalent modification caused by sarin in the acetylcholinesterase active site.

i really wish i could answer this question for you

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."