Hemoglobin Carbonation & Protonation

in this video, we're going to begin our discussion on hemoglobin, carbonation and pro nation. So at this point in our course, we already know that hemoglobin combined to carbon dioxide via carbonation and it can also bind two protons via pro nation. Now, in this video, we're mainly going to talk about hemoglobin carbonation. But in our next video, we'll talk about hemoglobin protein nation. Now, most of the information in this video is actually going to be review from our previous lesson videos. But we are going to reveal some critical information about hemoglobin carbonation that you guys should be familiar with. So we already know that hemoglobin carbonation can be referred to as just h B C 02 and hemoglobin. Carbonation occurs mainly in the tissues, not in the lungs. Now this allows hemoglobin to directly transport some small amount about 10% of the carbon dioxide from the tissues to the lungs. Now, this next bullet point here is going to reveal the critical information that we need to know about hemoglobin, carbonation. And so at this point we know that hemoglobin has four separate sub units and so each of hemoglobin is four separate sub units can actually bind to a carbon dioxide molecule forming a carbonate group on each of the free Alfa amino groups on each of hemoglobin, subunits, toe form what we call carb amino hemoglobin, which is just hemoglobin with carbonate groups bound and again. This is where we're going to refer to as H B Co two. And so, if we take a look at our image down below notice, we're showing you the formation of carb amino hemoglobin and notice that this molecule over here on the far left is our co two molecule are carbon dioxide molecule and then in red right here. What we have is hemoglobin and terminal amino acid residue. Essentially, the free Alfa Amino group is right here at this position. And so notice that this reaction right here will release a proton and in the meantime, it forms the carb amino hemoglobin. And so this is going to have just a carbon dioxide molecule attached as a car box, Late group and together, this car box like group attached to this nitrogen here forms the carbonate group and together this entire thing is referred to as carbon, you know, hemoglobin. HB co two. And what's important to note is that again, this is just showing the reaction for just one of the sub units of hemoglobin interacting with co. Two. However, remember that each of hemoglobin subunits can undergo this reaction. And so what this means is that if we consider the hemoglobin four sub units, each of the four subunits combined ah CO two molecule and so four co two molecules can be transported by one Chema Global. And so recall from our previous lesson videos that hemoglobin carbonation stabilizes the T state, which is the 10th state and binds ligand, or oxygen inefficiently. And so, if we stabilize the T state, that's going to cause the release of oxygen. And so notice over here on the left, where hemoglobin is carbonated, it's present in the T state and notice it's not bound toe any oxygen. And so the reason for this is because in the tissues there is such a high partial pressure of carbon dioxide, lots of carbon dioxide being produced in the tissues. And so there's so much carbon dioxide that hemoglobin is bound to bind to some of that carbon dioxide so hemoglobin gets carbonated at thes high partial pressures and, of course, that stable as the T state and caused the release of oxygen. And so that's why we can see over here we have the T state of hemoglobin in the tissues. So here we have a bicep to represent the tissues. And again, this has to do with the high partial pressure of carbon dioxide in the tissues so high that hemoglobin is bound to bind to some of that CO two Now in the lungs, there's the complete opposite condition of low partial pressure of CO two in the lungs because we're constantly exhaling co two. And so because we're breathing out all of that, CO two hemoglobin is going to be de carbonated, essentially releasing the CO two so that it can be exhaled as well. And now the hemoglobin molecule is going to be in the our state when it's in the lungs. And again, this has to do with the low partial pressure of CO two in the lungs. And so basically, the main take away here is that hemoglobin carbonation occurs Onley in the tissues as we can see over here, and essentially carb amino hemoglobin is just referring to him. A globe in that's bound to co two molecules. So this year concludes our lesson on hemoglobin. Carbonation will be able to get a little bit of practice in our next video, and then we'll move on to hemoglobin Probe nation. So I'll see you guys in our next video.

So now that we've covered hemoglobin carbonation in this video, we're going to focus on hemoglobin pro Nation, which we already know from our previous lesson. Videos can be abbreviated as just h h b plus. And so, just like hemoglobin, carbonation, hemoglobin, pro nation occurs Onley in the tissues, not in the lungs. And so what's important to note about hemoglobin prote nation is that hemoglobin can actually become protein ated on several amino acid are groups in order to carry H plus as H H B plus. And because it's actually these are groups that are susceptible to protein nation. This means that their arm or protein nation sites than there are carbonation sites and so recall in our previous lesson video. When we talked about hemoglobin carbonation, we said that it's on Lee, the free Alfa amino groups that can be carbonated, and there are only four free Alfa amino groups of there are only four carbonation sites. However, here with hemoglobin pro nation again, it's the are groups that are being pro nated and so there are several amino acid are groups that can be pro nated in hemoglobin structure, and so notice down below. Here we're showing hemoglobin structure being protein aided and noticed that there are way more pro nation sites than there are carbonation sites. And so what's important to know is that in the relatively high concentration of hydrogen ions, or low pH of the tissues there are is so much hydrogen ion concentration that hemoglobin is bound to grab onto one of those hydrogen ions and become protein ated to form H H B plus. And, of course, that's going to stabilize the T state and release oxygen. And so, if we take a look down below, noticed that when hemoglobin is protein ated as H H B plus, it's going to be stabilizing the T state. It's going to be releasing oxygen on. This is all due to the low pH in the tissues or the high hydrogen ion concentration in the muscle tissues. Now in the lungs, we have the complete opposite concentration of hydrogen ion, so we have very, very low concentration of hydrogen ion or ah, high pH in the lungs. And there's such a low concentration of hydrogen ion that hemoglobin is going to be deep protein ated to release H plus. And of course, when it releases H plus. It can then bind toe all of the oxygen that's present in the lungs, and so that allows it to bind oxygen in the our state. And again, this is due to the low. I'm sorry, the high pH in the lungs and the low concentration of hydrogen ion. And so this here concludes our lesson on hemoglobin prote nation, specifically in the tissues. And again, that is really the main take away here, that hemoglobin, pro nation, as well as hemoglobin, carbonation both occur in the tissues and not in the lungs. And so I'll see you guys in our next video, where we'll be able to apply some of these concepts.

in this video, we're going to do a quick recap on hemoglobin, carbonation and pro nation. And so notice looking down below at our image on the left hand side. Over here we're zooming in specifically into the bloodstream by the tissues, and so notice that end the tissues. We have a very, very high concentration of CO two, which is going to lead to a high concentration of H plus in the tissues. And so there's so much co two and so much H plus in the tissues that him, a global, is bound to bind to the H Plus and C +02 And, of course, when it binds to the H Plus and Co. Two, it's going to be in its ti state and release oxygen. And then, of course, myoglobin can facilitate the oxygen to diffusion into the tissues now in the lungs. On the other hand, notice that there is the exact opposite conditions as the tissue, so there's a very, very low concentration of CO two. And of course, the low concentration of CO two translates to the inside of the red blood. So and the Low Co two causes these equilibrium is here to shift to the right to compensate, and that's going to decrease the concentration of hydrogen ion. So we have a low concentration of CO two and a low concentration of hydrogen ion. And so it's so low that hemoglobin is bound to release some of its hydrogen ion so that it can also participate in this shift to the right, and it can release its CO two so it can also be breathed out of the cell. And so, of course, when it releases the H Plus and Co. Two, it can also bind to the very, very high concentration of oxygen that's constantly being breathed in. And so hemoglobin is going to bind the oxygen, release the H Plus and Co. Two and be present in its our state when it's in the lungs. And so this here is our brief recap on human global carbonation of pro nation. And again we'll be able to talk Maura about these ideas as we move forward in our course. So I'll see you guys in our next video