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Physiology & Medicine / How exactly do molecules 'fit' into receptors?
« on: 13/11/2014 02:39:44 »
I regularly listen to AskTNS and I get slightly confused whenever the scientists talk about molecules fitting into a receptor.
So for example there was an episode that said something along the lines of some molecule in Propranolol 'fits'
inside a receptor in the heart that otherwise adrenaline (or something) would usually fill except the Propranolol
doesn't allow salt through which as a result lowers the heart rate.
OK so, what do we mean when we say these chemicals 'fit' into the receptor, or are these terms just like an analogy for
a chemical attraction between molecules, or is it literally, the molecule fits perfectly into a receptor.
If the latter is the case, I just imagine the following: A washing machine is the body, you put a bunch of padlocks and
a load of keys in the washing machine, if you turn it on with all the locks and the keys swishing around, even though the
keys (molecules) fit in all the locks (receptor) and they're going around the washing machine (the body), they wouldn't
just fall into the right shape lock, they still need to be pushed in by intervention.
So how do these molecules just happen to 'fall' into the right receptor, even if they do fit...like the keys and locks in the washer,
unless they're forced in, how do they actually get in there.
Apologise for the simple language, analogies and metaphors there but if I can visualise something it helps me understand.
Cheers.
PS. I'm on mobile so I'm sorry if the layout of this looks odd, the box isn't rendering all that we'll for me.
So for example there was an episode that said something along the lines of some molecule in Propranolol 'fits'
inside a receptor in the heart that otherwise adrenaline (or something) would usually fill except the Propranolol
doesn't allow salt through which as a result lowers the heart rate.
OK so, what do we mean when we say these chemicals 'fit' into the receptor, or are these terms just like an analogy for
a chemical attraction between molecules, or is it literally, the molecule fits perfectly into a receptor.
If the latter is the case, I just imagine the following: A washing machine is the body, you put a bunch of padlocks and
a load of keys in the washing machine, if you turn it on with all the locks and the keys swishing around, even though the
keys (molecules) fit in all the locks (receptor) and they're going around the washing machine (the body), they wouldn't
just fall into the right shape lock, they still need to be pushed in by intervention.
So how do these molecules just happen to 'fall' into the right receptor, even if they do fit...like the keys and locks in the washer,
unless they're forced in, how do they actually get in there.
Apologise for the simple language, analogies and metaphors there but if I can visualise something it helps me understand.
Cheers.
PS. I'm on mobile so I'm sorry if the layout of this looks odd, the box isn't rendering all that we'll for me.