Question

Acetylcholinesterase is an enzyme that catalyzes the breakdown of the neurotransmitter acetylcholine. Which of the following explains why acetylcholinesterase cannot be used to catalyze the breakdown of other neurotransmitters, like norepinephrine?


Binding with an alternate neurotransmitter would inhibit the reaction of the enzyme with acetylcholine.
Its shape determines the neurotransmitters that can reach its active center where activation energy is lowered.
It would require a level of activation energy too high for acetylcholinesterase to react with other neurotransmitters

Answer 1

Binding with an alternate neurotransmitter would inhibit the reaction of the enzyme with acetylcholine.
Its shape determines the neurotransmitters that can reach its active center where activation energy is lowered.
It would require a level of activation energy too high for acetylcholinesterase to react with other neurotransmitters.
Reacting with another neurotransmitter would halt the production of the enzyme and raise the overall activation energy.

Answer 2

They're not compatible, norepinephrine does not bind to the AchE active site therefore it catalyses no reaction in it. Watch this 1 minute video of "Lock & Key model"
http://www.youtube.com/watch?v=EiMBsgNZh-M

Answer: "Its shape determines the neurotransmitters that can reach its active center where activation energy is lowered."

Should you require further explanation i'd be happy to oblige