in this video, we're going to talk about the different antibody classes. And so it turns out that there's actually five different classes of antibodies or, in other words, five different classes of immuno globulin. It's and so these five classes are based on differences in their heavy chains as well See down below in our table. And so the five classes of antibodies R i G I g A I g m i g e n I g d. And if you look at these red letters here, notice that it spells gamed. And so notice down below. Right here we have this anybody stick figure playing some video games and based on his facial expression, I'd say he's pretty gamed out from playing video games for 72 hours straight. And so hopefully this antibody stick figure, along with gamed will help you guys remember the five different classes of antibodies. And so, looking at this table right here, what I want you guys to notice is that the light chain for all five classes of antibodies is exactly the same. So the light chain, why, there'd be the one that's represented by the Greek Letter Kappa or the light chain represented by the Greek letter Lambda. And so the light chain is not going to distinguish one antibody class from another. However, looking at the heavy chain notice that each class of antibody has a unique heavy chain. And so it's the heavy chain that's going to distinguish one antibody from one antibody class from another. And so this first row of antibody, this first class of antibody is I G. And this is really the one that we've been talking about all along and so you can see the Y shaped structure here that we talked about. Now, notice that I G e n I G have very similar type of structures. Toe i G. However, I G a forms a dime er of these two y shaped structures, and I g m tends to form a Penta mur uh, containing five different y shaped structures here. Now, over here in this column, what we have is the primary feature of each of these antibodies. Now I G is actually the most prevalent and the most abundant antibody in our blood. So this is going to be one that's involved on protecting pretty much against all types of infections, including bacterial and viral infections. Now I g. A is actually going to be highly concentrated in mucus membranes, and it's going to be one that is typically secreted by ourselves, and it's also prevalent in our saliva. Now I GM, interestingly enough, is usually going to be the first antibody that's going to be produced upon infection. So I GM, is going to be the one that's going to initiate the primary immune response. So the very first immune response and then the common second immune response would be I G. Since it's so prevalent in our Bloods now, I g. E, on the other hand here, is going to be one that's going to defend against allergies or allergies. And so you can see here we have a guy who's saying I'm allergic to this kitty cat right here, and that's unfortunate because this is a cute little kitty cat, but again is gonna help defend against these allergens. Now I G. D. Is one where its function is not really very well characterized. However, there are some text books and studies that say they're involved with activating B cells and allowing B cells. Thio participate in immune responses. Now, over here on the far right, what we have is the distribution of these antibodies, uh, classes throughout our bodies. And so notice that pretty much all of the antibodies they're gonna be found in our bloodstreams. Except for I G, which again is going to be highly concentrated in our mucous membrane. So it's gonna be lining our digestive systems a lot. And so this here concludes our introduction to the antibody classes, and we'll be able to talk more about antibodies as we move along in our core. So I'll see you guys in our next video.

in this video we're going to talk more details about the I. G. Class of antibody. And so the I. G. Antibody is the standard antibody. And that is because the I. G. Antibodies are the most abundant Antibody class in our blood and in our tissues. And in some individuals the I. G antibodies can make up to 80% of all of the immunoglobulins. Now these I G. G antibodies can have a variety of different functions. However they are capable of binding to very specific antigens and they can eliminate pathogens by activating the complement system classical pathway which recall we covered the complement system classical pathway. In our previous lesson videos when we discussed innate immunity. Now I G. G antibodies are also well known for providing immunity to a developing fetus during pregnancy as well as providing immunity to a newborn child after the child has been born. And so this is because these I. G antibodies have the amazing ability to cross the placenta between a mother and the baby. And so the mothers I. G antibodies are capable of crossing the placenta to protect the baby. So literally the mother is protecting the baby with her antibodies now also I G antibodies are well known for having a long half life. And all that means is that if it has a long half life is that it's very very stable. And it is capable of lasting a long time within our bodies before it's broken down. And so this long half life actually extends the time of protection of a newborn through the first few months after birth until the baby is capable of generating its own antibodies. And so basically what we're saying here is that literally a mother's antibodies protects the baby as the baby is a developing fetus. And for the first few months of the baby's life until the baby is capable of generating its own antibodies. And so if we take a look at our image down below it's just an image emphasizing those important features of the I. G. G. Class of antibodies and so notice that its structure is going to be that standard antibody structure that we talked about in our previous lesson videos notice it is the most abundant class of antibodies. Around 80% of the antibodies are gonna B. I. G. It provides infant immunity during again pregnancy as well as after childbirth as well because the I. G. G. Anybody has that amazing ability to cross the placenta between the mother and baby and last but not least this I. G. Antibody has many different immune functions including the ability to activate the complement system via the classical pathway where it can bind to antigens. And again you can see activating C. three convert taste leading to many different types of complement system uh activities such as inflammation optimization, sell license of microbes and so on. And again if you don't remember these details here about the complement system classical pathway. Be sure to go check out our older lesson videos on that content. But for now, this here concludes our brief lesson on the I. G. G. Class of antibodies. And as we move forward in our course, will also be able to discuss briefly some of the other classes of antibodies. So I'll see you all in our next video.

in this video we're going to briefly discuss the I. G. A. Class of antibodies and so the I. G. A. Class of antibody is going to help protect mucous membranes throughout our bodies. And they can also be found in body secretions such as for example saliva tears and breast milk. Now the I. G. A. Antibody is commonly found as a dime er which means that it consists of two identical subunits that are held together. And this dime er is referred to as secret Torrey I. G. A. Or S. I. G. A. For short. And within this secret Torrey I. G. A molecule which is a dime. Er it consists of two monomers that are held together by a peptide and we'll be able to see that down below in our image. Now the secret story I. G. A. Antibody and breast milk helps protect the intestinal track of breastfed newborns. Which is why breastfeeding can actually be very healthy for newborn babies to provide them with those I. G. A antibodies that can help protect again the intestinal track of those newborns. And so if we take a look at our image down below, we're just emphasizing those same important details of the I. G. A. Antibody. And uh again the I. G. A. Antibody is commonly found as a dime er that we referred to as secret Story I. G. A. And so what you can see here is that there is a dime er there's this unit right here and then there's this other identical unit right here and these two units are held together by this blue peptide that is swirling around it. And so that is the secretary I. G. A. Antibody. Again this is really good going to be important for protecting mucous membranes throughout our bodies. And also it's going to be found in mucus, saliva tears and breast milk. And so you can see those images down below and again because it is found in breast milk, it will help protect the intestinal track of newborn babies that are breast fed. And so you can see the I. G. A. Antibody here dissolved within this breast milk. And so this year concludes our brief lesson on the I. G. A. Class of antibody. And again we'll be able to get some practice applying these concepts and talk about the other classes of antibodies briefly as we move forward. So I'll see you all in our next video.

in this video we're going to briefly discuss the I. G. M. Class of antibodies. And so the I. G. M. Antibody is very important for controlling infections in the blood and it is actually the very first antibody that is going to be initially produced in a primary infection by plasma cells. Before a process known as class switching takes place. And later in our course in a different video we'll talk more about this antibody class switching. Now the I. G. M. Class of antibody is also the largest class of antibody in terms of its size and molecular mass. Because I G. M antibodies consists of a pen Timur which means that it is composed of five identical why shaped subunits and because it has five Y shaped subunits, each subunit with two antigen binding sites that means that there are antigen binding sites. And because there are so many antigen binding sites on these gM antibodies that makes them very very effective at linking antigens together. Now the large size of the I. G. M. Antibody class actually prevent the I. G. M. Antibody from leaving the blood into the tissues. And so that's why the I. G. M. Antibody. Its primary role is to help control infections in the blood. Also, the I. G. M. Class of antibody is the most efficient antibody class at activating the complement system via the classical pathway. And so if we take a look at our image down below. Once again we'll have an image that helps to emphasize those same features of the I. G. M. Class of antibodies notice first that it is indeed a pen Timur that consists of these five identical Y shaped sub units and so that makes it the largest antibody class so we can label it here as the largest antibody class and size. Also it is the very first antibody that is initially created by all plasma cells prior to the antibody class switching process that we'll get to talk about in more detail later in our course and the primary role of the I. G. M. Antibody because of its large size is to control infections in the bloodstream. Also this is the most effective antibody at activating the complement system so it activates the complement system when it binds to the antigen. And again here we have a little image that shows you see three convert taste being generated upon activation of the complement system and then all of these um actions that result from the complement system activation including inflammation optimization and sell license of microbes. And again if you don't remember much about the complement system, make sure to go back to our older lesson videos to check those out. But again this year concludes our brief lesson on the I. G. M. Class of anybody and we'll be able to get some practice applying these concepts and talk about the other classes as we move forward. So I'll see you all in our next video

in this video we're going to talk briefly about the I. G. E. Class of antibody. And so the I. G. E antibodies are found on the surface of both Beso fills and mast cells. And recall that beso fills and mast cells are going to have a lot of similarities but recall that beso fills will circulate through the bloodstream whereas mast cells are more localized within specific tissues. And so when these I. G antibodies are on the surface of beso fills and mast cells they're capable of detecting and responding to very specific antigen. And these I. G. E antibodies can actually cause the cell to undergo a process called degranulation which you might recall from some of our previous lesson videos just means that it will cause these cells to release their Granules and the contents of their Granules into the environment and so that can include releasing inflammatory mediators that lead to inflammation in response to some kind of infection. Now these I. G antibodies are very important for eliminating parasites such as worms and they're also going to play an important role in the response to many different types of allergic reactions or hyper sensitivities which we'll get to talk more about allergic reactions and hypersensitivity is much later in our course in a separate video. But for now if we take a look at our image down below we can get a more solid understanding of this I. G. E. Class of antibody and notice here it has that same antibody structure and again it's found on the surface of both Beso fills as well as mass cells. And so you can see the baseball field over here, the mast cells over here and upon binding their antigen, they cause degranulation, the release of the contents of the cytoplasmic Granules which could include inflammatory mediators leading to inflammation. And so this can these I. G. Antibodies are important for protecting against parasitic infections like those parasitic worms as well as again responding to uh allergies or generating those allergic reactions. And again we'll get to talk more about allergies later in our course. But for now this here concludes our brief lesson on the I. G. Class of anybody and we'll be able to get some practice applying these concepts and then talk about the very last class of anybody. So I'll see you all in our next video.

in this video we're going to talk very briefly about the I. G. D. Class of antibody. And so I G. D antibodies are found on the surface of B cells and they signal B cell activation and maturation into an antibody secreting plasma cell. And so really these I G. D antibodies are important for the development and maturation of the antibody response. And so if we take a look at our image down below we can see here that the I. G. D. Antibody is again a monomer that you can see here. That makes up a very small percentage of all of the antibodies. About 1% of all the antibodies. And again it's going to be found. It can be found on the surface of B cells as you see here and their role on the surface of B cells is again to help the B cell differentiate into plasma cells that can secrete antibodies. And so the I. G. D. Antibody is going to help activate the B cell and help it differentiate into a plasma cell. And ultimately the plasma cell will be able to secrete a variety or different types of antibodies. And so this year concludes our brief lesson on the I. G. D. Antibody and its role in the development and maturation of the antibody response. And we'll be able to get some practice applying this as we move forward. So I'll see you all in our next video

in this video we're going to do a quick review of all of the immunoglobulin classes or all of the classes of antibodies. And so we're going to do that by completing this review table of the immunoglobulin classes. And so what you'll notice is that we have these five classes of antibodies arranged so that they fit our pneumonic which is gamed. And the I. G. G antibodies. The very first one on this list notice that it is a monomer and it is the standard antibody. Uh it has a very very long half life which means that it's very stable and will last a long time within our bodies before it's broken down. It is the most abundant class of antibody. Around 80% of all antibodies will b. I.g. It has this amazing ability to cross the placenta between the mother and the baby which is going to help provide the fetus uh immunity during pregnancy as well as even after birth. Because again these I. G antibodies last such a long time that the mothers I. G. G. Antibodies and the baby will also help to protect the baby even after birth. And they're also important for activating the complement system which can lead to a variety of immune responses. Now the I. G. A antibody notice it is a dime er and a lot of times we refer to this dimmer as the secret story. I. G. A. Antibody or S. I. G. A antibody notice that its half life is medium and it's going to be important for protecting the mucous membranes. It's also found in many different types of body secretions including breast milk which can help protect the infant's intestinal system when a mother breast feeds her baby. The next antibody that we have on here is the I. G. M. Antibody which is the largest class of antibodies. It is a pen Timur and its half life is medium and it is the very first antibody that is initially created by all plasma cells. Prior to antibody class switching. It helps to control infections in the bloodstream that is its main role and it also is the most effective class at activating the complement system. The next class that we have here is the I. G. E. Antibody which again is a monomer and its half life is very very short. Uh And so it is going to be found on both the surfaces of beso fills as well as mass cells. And they're important for triggering the release of inflammatory mediators causing these beso fills and mast cells to d granulated releasing their Granules into their environment. Uh The inflammatory mediators can cause inflammation and the I. G. E. Antibodies also play a role in allergic reactions and we'll get to talk more about that later in our course when we focus our attention on allergic reactions and hypersensitivity. Uh They also play an important role in protecting against parasitic infections as well like parasitic worms for example now last but not least we have the I. G. D. Antibody which is again a monomer and has a short half life, which means that it does not last very long within the body. Uh Now the I. G. D. Antibodies are going to be found on the surface of B cells or can be found on the surface of B cells and they play an important role in helping to trigger B cell activation and differentiation into antibody secreting plasma cells. And so this here concludes our brief review of the five classes of antibodies and we'll be able to get some more practice applying these concepts as we move forward. So I'll see you all in our next video.