In this video, watch as Leslie explains how agonists and antagonists affect the receptor sites of the cell.
Enjoy!
Transcript of Today’s Episode
Hello and welcome to another episode of Interactive Biology TV, where we’re making biology fun! My name is Leslie Samuel. In this episode, Episode 18, I’m going to be talking about agonists and antagonists. It almost sounds like a plot for a movie, but it’s not a movie, unless it’s a movie happening inside your body. Anyhow, for today, let’s get into what we’re going to be talking about.
The first thing we’re going to talk about is “What is an agonist?” An agonist is a molecule that mimics the effect of a neurotransmitter, so it does what that neurotransmitter would normally do. An example of that would be succinylcholine mimics the neurotransmitter acetylcholine. So what I’m going to do is I’m going to draw the receptor here, and here we have the cell membrane of the neuron. I’m going to draw it a little different than I’ve been drawing it before. I’m going to have these as the receptor sites. This is where the acetylcholine normally binds to the nicotinic receptor.
I’m going to draw acetylcholine here, but I’m not going to draw it coming here. What I’m going to do is I’m going to draw something that’s slightly different, let’s just say it’s a different color. It’s a similar shape to acetylcholine, and we’re going to call this succinylcholine. When that comes here and it binds to the receptor, same thing here, it comes and it binds to the receptor, the channel opens, which is what it would normally do if acetylcholine binds. And then, sodium ions on the outside end up coming inside the cell. So this would be an example of an agonist. It’s not acetylcholine, it’s something else, and let’s say, in this case, it’s succinylcholine, and that comes, binds to the receptor and causes a similar response. That is an agonist.
Now, let’s look at what an antagonist is. You can probably guess just by reading the word, but an antagonist is a molecule that opposes the effect of a neurotransmitter. So it does the exact opposite. An example of that would be curare, which is an antagonist to acetylcholine that can actually block the binding sites for acetylcholine. So here, we have our nicotinic receptor again, and it’s in the membrane of the cell, and here we have the binding sites.
Out here, we have acetylcholine that wants to bind. However, we have something else that’s around that’s not exactly like acetylcholine and let’s say that its shape looks something like this. That binds to the receptor, and what that does is it blocks the receptor site. So acetylcholine wants to bind and it wants to cause that channel to open, but it’s being blocked so that it cannot bind, and it cannot open the channel for sodium to come in. This would be an example of what curare does. It’s an antagonist, and in fact, curare can cause muscles to become paralyzed because they cannot be activated and sodium cannot rush into the cell, exciting the cell, and exciting the muscle to contract. So that can be a serious thing if you have curare binding to these receptor sites.
That’s really all for this video. I hope you understand the difference between an agonist and an antagonist. If you have any questions or comments about that, go ahead and leave them below. I’ll be happy to answer your question, and maybe even make a follow-up video answering your specific question. That’s it for this video, and I’ll see you on the next one.
About The Author Leslie Samuel
Leslie Samuel is the creator of Interactive Biology. He created this site to help Make Biology Fun and has the goal of making this the biggest and best biology resource on the net.
so can someone answer my question?
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Hi! I’m so sorry, but Leslie is busy with a lot of stuff right now. He just doesn’t have the time to be able to go through each mail he gets but, he’s working on more videos and he might just touch more about this topic. So, please stay tuned for more! You can try to go to our Facebook Fan Page community, too. There are some who would answer Biology inquiries from there.
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@msss432 Hi! I’m so sorry, but Leslie is busy with a lot of stuff right now. He just doesn’t have the time to be able to go through each mail he gets but, he’s working on more videos and he might just touch more about this topic. So, please stay tuned for more! You can try to go to our Facebook Fan Page community, too. There are some who would answer Biology inquiries from there.
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Hi! I’m so sorry, but Leslie is busy with a lot of stuff right now. He just doesn’t have the time to be able to go through each mail he gets but, he’s working on more videos and he might just touch more about this topic. So, please stay tuned for more! You can try to go to our Facebook Fan Page community, too. There are some who would answer Biology inquiries from there.
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drugs can be examples of antagonists or agonists.
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@msss432 drugs can be examples of antagonists or agonists.
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so when you take a certain drug it can either work as an agonists by enhancing the effect of a neurotransmitter, or it can work as an antagonist and prevent the neurotransmitter from working.
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@xamandaxgatewayx so when you take a certain drug it can either work as an agonists by enhancing the effect of a neurotransmitter, or it can work as an antagonist and prevent the neurotransmitter from working.
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drugs can be examples of antagonists or agonists.
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so when you take a certain drug it can either work as an agonists by enhancing the effect of a neurotransmitter, or it can work as an antagonist and prevent the neurotransmitter from working.
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wow…i just got taught by Mike Tyson…i feel privileged..great vid
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wow…i just got taught by Mike Tyson…i feel privileged..great vid
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hi, I only know about curare…I was taught that its an arrow poison…so, imagine one trying to shoot an animal and all of a sudden, ‘mistakenly’ shoots a person around…it will act… (thats the little I know about how it can get there)…
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@msss432 hi, I only know about curare…I was taught that its an arrow poison…so, imagine one trying to shoot an animal and all of a sudden, ‘mistakenly’ shoots a person around…it will act… (thats the little I know about how it can get there)…
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hi, I only know about curare…I was taught that its an arrow poison…so, imagine one trying to shoot an animal and all of a sudden, ‘mistakenly’ shoots a person around…it will act… (thats the little I know about how it can get there)…
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thank youuu
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thank youuu
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@msss432
Succinyl-choline (the antagonist) is a medication used in Healthcare, especially in anesthesiology (where people are sedated for surgery). It causes the muscles to relax so it’s easier to work with the body (i.e. intubation, cutting through muscle, opening the cuts)
The antagonist is also a type of medication, lots of examples here. It also causes relaxation, but does so in a different manner (as explained in the video).
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Succinyl-choline (the antagonist) is a medication used in Healthcare, especially in anesthesiology (where people are sedated for surgery). It causes the muscles to relax so it’s easier to work with the body (i.e. intubation, cutting through muscle, opening the cuts)
The antagonist is also a type of medication, lots of examples here. It also causes relaxation, but does so in a different manner (as explained in the video).
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@Yorreh20 I Meant “Agonist” in the example of succinyl-choline
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I Meant “Agonist” in the example of succinyl-choline
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Succinyl-choline (the antagonist) is a medication used in Healthcare, especially in anesthesiology (where people are sedated for surgery). It causes the muscles to relax so it’s easier to work with the body (i.e. intubation, cutting through muscle, opening the cuts)
The antagonist is also a type of medication, lots of examples here. It also causes relaxation, but does so in a different manner (as explained in the video).
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I Meant “Agonist” in the example of succinyl-choline
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Leslie,
Thank you so much for explaining and drawing out the differences between an agonist and an antagonist. You did an awesome job at breaking this concept down and now I can understand it completely! Sincerely,
Michele
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Lrsamuel Reply:
January 22nd, 2012 at 9:29 pm
Thanks for the feedback Michele!
All the best.
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Thank you so much, we are currently studying this in college, and to be honest i was very confused, but you made it very interesting, and i finally understand what is actually going.. Thank you again
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Thank you so much, we are currently studying this in college, and to be honest i was very confused, but you made it very interesting, and i finally understand what is actually going.. Thank you again
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What is the difference between agonist and reuptake inhibitor?
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@BondComputer007
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It’s my understanding is agonist and antagonists (same compounds can be both) depends on the effect they are going to have. A drug that might act as an antagoist for one compound might act as an antagonist. Some can be in the body, or administrated drugs via oral, iv and other routes of administration. I think that’s the best way to exam it. Have a read of some pharmcology text books
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It’s my understanding is agonist and antagonists (same compounds can be both) depends on the effect they are going to have. A drug that might act as an antagoist for one compound might act as an antagonist. Some can be in the body, or administrated drugs via oral, iv and other routes of administration. I think that’s the best way to exam it. Have a read of some pharmcology text books
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I would like to know this as well.
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I would like to know this as well.
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don’t confuse the nervous system with the muscular system hehe (inside joke)
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don’t confuse the nervous system with the muscular system hehe (inside joke)
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thank you very much I wish the best for this website and for the owner
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Thanks! This was very helpful to my Psychology study guide.
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i want to know difference between types of antagonist ?
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Brilliant again. These videos are really helping me get my head around this subject.
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Thanks, you make these hard subjects easy to understand
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Can you please make a video regarding Chemical Antagonism sir?
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simple and easy to understand
thank you
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Plain n simple…. Thank you!!!!:)
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Very clear, can you please explain the functions of a receptor.
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Thank you
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Really simply and easy to understand! Thankyou so much, this is helping my Medications class
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Thank you Leslie, you are the best!!!! Btw, after watching some of your videos onhow action potential works in our brain. And other videos relating to the physiology of the brain I Aced my exam
Thank you for all you do. I’m always watching and looking forward for more of your videos
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Leslie Samuel Reply:
May 13th, 2013 at 3:54 pm
Woohoo, that’s so awesome. Congrats on Acing your exam. You rock!
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