So at this point, our course, we're already familiar with hemoglobin binding in the tissues and lungs, as well as hemoglobin, carbonation and pro nation. And really, all of that was just background information to help us understand the boar effect, which is what we're going to talk about in this video. And so really, the boar effect is just giving a name to a process that we're already familiar with from our previous lesson videos. And so really, most of the information in this video is just going to be review. And really, there's just a small bit of new information that we're going to reveal here. And so what we need to recall from our previous lesson videos is that the Boer Effect describes the effect of the concentration of CO two as well as the effect of pH, or the concentration of hydrogen ions on both hemoglobin binding and release of oxygen. And so recall from our previous lesson videos that carb, amino hemoglobin, or H B C 02 as well as protein ated, hemoglobin, H H B plus both stabilize the T state of hemoglobin to promote oxygen release. And so, if we really take a look at this boar effect. Really? What it says is that when the concentration of CO two and H plus are both really, really high as they are in the tissues, they are both going to act as ballast Eric inhibitors and three significant events are going to occur at these high concentrations, and those three events are right down below and again there really just review from our previous lesson videos. And so there's such a high concentration of CO two in the tissues that hemoglobin is just bound to bind to some of that CO two as carb amino hemoglobin, HB C 02 And similarly, there's also such a high concentration of H plus in the tissues that again hemoglobin is bound to buying to some of the H plus and become protein ated as HP plus. And so if hemoglobin is bound to co two and thes protons, it's basically going toe these air basically going to act as an inhibitor and decrease hemoglobin oxygen affinity. So hemoglobin, oxygen affinity is going to be decreased, leading to oxygen release. And so again, everything that we have here in Green is pretty much just review from our previous lesson videos. And so ultimately, what we're saying that's new here is that because CO two and H plus act as ballast Eric inhibitors, they're going to cause a shift of the oxygen binding curve to the right, and we will be able to see that down below once we take a look at our oxygen binding curve. Now, the last point that I wanna make here that is actually also review from our previous lesson videos is that when the concentration of CO two and H plus are low as they are in the lungs, then the complete opposite events are going to take place that we mentioned up above. And so instead of hemoglobin binding CO. Two, it's gonna release CO two. Instead of binding or being protein ated, it's gonna be it's going to be deep rotated. And instead of decreasing 02 affinity, it's going to increase so too affinity. And so if we take a look at our oxygen binding curve down below notice that we have again the fractional saturation theater, or why on the Y axis, as well as the partial pressure of oxygen and units of tours on the X axis, and then we've got these three different curves here. We've got the blue curve, we've got the red curve and we've got the green curve and so you'll also notice that end the background. What we have is the partial pressure of oxygen in the lungs, which is right around 100 tours. And we have the partial pressure of oxygen and the tissues, which is right around 20 tours. And so what, you'll notice over here on the right is we have the boar effect. And so, as we mentioned up above, there is going to be a shift to the right, a right shift in the tissue so the oxygen binding curve is going to shift to the right. And so, as we can see over here, this green curve is indeed shifted to the right with respect to the red curve, which is representing hemoglobin is binding under normal conditions when it's neither in the tissues or in the lungs. And so, with this green curve right here, what we can see is that there is a right shift in the tissues and a right shift here in the, uh, tissues with this curve is going to lead to a high K D and a high K D leads to a low oxygen affinity. And so there's a low oxygen affinity. Of course, that means that it's going to release more oxygen. And so this is all due to the fact that in the tissues there's such a high concentration of CO two so high partial pressure of Co two. There's also a high concentration of H plus. Of course, a high concentration of H plus leads to a lower pH with a pH value of about 7.2 in the tissues, just as we can see over here indicated on the curb. And then, of course, because there's a lower oxygen affinity due to the CO two and H plus acting as inhibitors, this is going to increase the oxygen release to the tissues. Now, if we take a look at the conditions in the lungs that's going to be represented by this blue curve, and of course the opposite events are going to occur. And so instead of having a shift to the right, there's going to be a shift to the left, and so we can see down. Below are blue Curve is indeed shifted to the left with respect to the red curve. And so we can say that there is a left shift in the lungs. And of course, the left shift in the lungs is going to cause the K d to be low. And of course, a lo que de corresponds with a high oxygen affinity. And again, this is all due to the fact that in the lungs were constantly exhaling co two. So the partial pressure of CO two is gonna be really low in the lungs. And so is the concentration of hydrogen ions and, of course, a low concentration of hydrogen ions. It's gonna lead to a relatively high pH right around a value of about 7.6 and lungs just like we can see over here in our graph. And then, of course, a higher oxygen affinity is going to lead to less oxygen release, so less oxygen is gonna be released and mawr oxygen is going to be bound. And so really, what you'll notice is that literally the longs over here is the complete and exact opposite of the tissues in terms of the up and down arrows and the highs and lows as well as the left and the right shift. So pretty much everything is opposite in the lungs versus the tissues. And so, really, this together all describes the boar effect. And so what you'll notice is that the Boer Effect, really what it allows hemoglobin to do, is switch from the blue curve to the green curve when it is transitioning from the lungs to the tissues. And so, essentially, if you take a look at this oxygen binding curve up above. When hemoglobin is in the lungs, it's going to take on the blue curve that we see here. And when hemoglobin is in the tissues, it's going to take on the green curve. So there is this transition from the blue curve to the green curve. On that transition is what's referred to as the boar effect. And so what the boar effect allows is for him a global to maximize, its oxygen binding when it's in the lungs, and it also allows it to optimize its oxygen release when it's in the tissues on DSO. If we take a look up above, notice that with the blue curve here, when it's in the lungs. You'll notice that it has the highest binding of oxygen. And so, uh, hemoglobin is able to maximize again, maximize its oxygen binding in the lungs when it takes on the shape of the blue curve in the lungs, and then notice that as it starts to make its way to the tissues him, a global is going to switch from following the blue curve to following the green curve because of the decreased pH. And so in the green curve noticed that it has less oxygen bound, a lower fractional saturation than at the same point here as the blue curve. So we're comparing right where it hits this line here to the green curve, where it hits this line right here. And so this represents Mawr oxygen being released because there's, ah, lower fractional saturation. And so, essentially, this allows hemoglobin to maximize its binding in the lungs and maximize or optimize its release of oxygen to the tissues. And really, that is the board effect in a nutshell. And so this here concludes our lesson on the boar effect and will be able to get some practice utilizing these concepts as we move forward in our course. So I'll see you guys in our next video
Identify all the correct statements regarding the Bohr effect on hemoglobin.
i) The Bohr effect shifts the fractional O2 saturation curve to the right as pH decreases.
ii) The Bohr effect shifts the fractional O2 saturation curve to the right as pH increases.
iii) The Bohr effect favors O2 release in respiring tissues.
iv) O2 and H+ compete for the same binding site on hemoglobin.
i & iii.
i & iv.
ii & iv.
ii, iii, & iv.
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in this video, we're going to recap and summarize the boar effect on hemoglobin, and so notice in our table down below. On the left hand side, we're going to recap the Boer Effect as it pertains to the tissues. And on the right hand side, we're going to recap the Boer Effect as it pertains to the lungs. And so, of course, we know that there is a lower pH in the tissues due to production of hydrogen ions, whereas in the lungs there's a higher pH. Now hemoglobin is going to release oxygen in the tissues, whereas in the lungs, hemoglobin is going to bind oxygen. Now in the tissues. Hemoglobin is actually going to bind to the hydrogen ions that it's producing, whereas in the lungs it's going to release those hydrogen ions that it bound. And so notice down below. In our image, we have our little circulatory system right here, where you can see we have our hearts in the middle and you can see the bloodstream as it leads to the lungs on the bloodstream as it leads to the tissues. And so notice that in our tissues there's a High co two concentration and a low oxygen concentration, whereas in the lungs it's completely opposite. We have a low co two concentration and a high oxygen concentration and also noticed that we're zooming into the tissues over here on the left, whereas on the right, we're zooming into the lungs. And so really, this image that we have, uh, down below here is the same as our previous images. Except we're combining everything into one single, uh, sell for reviewing purpose is to make it easy, um, in terms of combining everything into one image. And so, essentially, what we're going to do is we're going to start off with the high concentration of CO two that's produced in our muscle tissues. And then what we'll do is we'll work our way through here like this, end up in the lungs and then come back, and, uh, and our story here in the tissues, okay. And so, of course, this high concentration of CO two is because our tissues are performing cellular respiration and all of this CO two is going to diffuse out into our blood stream into the red blood cell where there's gonna be a relatively high concentration of co two as well. And then in our red blood cells there's an enzyme, carbonic and hydrates that will catalyze a reaction with CO two and water. And of course, the High Co two is gonna cause this equilibrium to shift to the right to compensate. And that's why we have less affiliates principle here to remind us of that. And so that forms carbonic acid, which is relatively acidic here, and it's going to break up into its conjugate base and, um, the hydrogen ion here in the tissues and so in the tissues. Essentially, what we're saying is there's there's gonna be a production of hydrogen ion, Uh, just like what we mentioned up above. And so, of course, producing hydrogen ions is going to lead to a lower pH. And so the pH and the tissues is going to be slightly lower around 7.2, whereas in the lungs, what happens is this hydrogen ion is going to react to form water ultimately, And so this is all because in our lungs there's a low concentration of CO two because we're constantly exhaling co two. And so if there's a low concentration of CO two, then this equilibrium controlled by carbonic and hydrates is going to shift to the right to respond to the low concentrations of CO two on. Of course, that's going to occur. Villa shot Leah's principle, and, uh, that's gonna cause hydrogen ions to produce water. And, of course, a decrease in hydrogen ions is going to increase the pH slightly to a value of 7.6 in the lungs. Now, also in the lungs with every breath were inhaling a high concentration of oxygen. And all of that oxygen is going to defuse out of the lungs, into our blood capital, Aries, and into our red blood cells. And so, essentially, what happens is there's such a high concentration of oxygen that it's going to bind to our deok Sikkim, a global upon arrival to the lungs. And essentially, what's gonna happen is the hydrogen is gonna be released by hemoglobin, and this hydrogen will participate in this reaction and be formed into a water molecule, and the same goes for this CO two. It will essentially be defused out on exhaled out of the lungs. And so, while these hydrogen ions and CO. Two are going to be released, uh, the high concentration of oxygen is going toe. Replace and bind to the hemoglobin. And so we end up getting oxygenated hemoglobin in our lungs. And so all of this oxygen is capable of being transported to our tissues. And so once it gets to the tissues, hemoglobin is going to encounter a high concentration of hydrogen ions and, ah, high concentration of CO two. So it's going to bind to the hydrogen ions and CO. Two. And when it does that, of course, it's going to cause, uh, hemoglobin to release its oxygen in the tissues. And, of course, myoglobin in our tissues can help facilitate oxygen diffusion into the tissues. And so, really, that completes our full cycle here. And that is, uh, the end of this video. So we'll be able to get some practice in our next video. So I'll see you guys there
On the graph below, draw in the approximate shapes of the O 2-saturation curves in the lungs & tissues after a shift due to the Bohr effect takes place.
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The Bohr effect describes the change in hemoglobin’s affinity for oxygen under two different conditions. What are these two conditions and how do they impact hemoglobin’s affinity for oxygen? Complete the table below: