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So this is the double stranded DNA molecule that describes the interest, that describes the gene that we're studying. So what a restriction map is? It's basically a description of all the different locations found on this gene where our restriction enzymes can bind to and cleave that gene. So for example, let's suppose this gene has three different restriction sites. So here, here and here. And what that means is a type of restriction enzyme can bind onto these three locations and cleave that particular gene and those locations. | Restriction Map and Gel Electrophoresis.txt |
So for example, let's suppose this gene has three different restriction sites. So here, here and here. And what that means is a type of restriction enzyme can bind onto these three locations and cleave that particular gene and those locations. So that's what we mean by a restriction map. Now what exactly is the procedure in creating the restriction map? Well, the restriction map basically involves or creating the restriction map involves a process known as gel electrophoresis. | Restriction Map and Gel Electrophoresis.txt |
So that's what we mean by a restriction map. Now what exactly is the procedure in creating the restriction map? Well, the restriction map basically involves or creating the restriction map involves a process known as gel electrophoresis. And this will be the focus of this lecture. So we're going to focus on the process of gel electrophoresis that is used in the creation of the restriction map for any particular gene. So let's suppose we look at diagram A. | Restriction Map and Gel Electrophoresis.txt |
And this will be the focus of this lecture. So we're going to focus on the process of gel electrophoresis that is used in the creation of the restriction map for any particular gene. So let's suppose we look at diagram A. In diagram A, we have the following gene shown in black. So this is our gene. Let's suppose we expose this gene, this gene here, to a specific type of restriction enzyme we're going to call enzyme number one. | Restriction Map and Gel Electrophoresis.txt |
In diagram A, we have the following gene shown in black. So this is our gene. Let's suppose we expose this gene, this gene here, to a specific type of restriction enzyme we're going to call enzyme number one. Now what happens is once we expose the gene to this restriction enzyme, the restriction enzyme cuts or cleaves this gene at two different locations. So at this location, somewhere here, and in this location somewhere here. So at the end, once we expose this gene to this enzyme, we get three different DNA fragments. | Restriction Map and Gel Electrophoresis.txt |
Now what happens is once we expose the gene to this restriction enzyme, the restriction enzyme cuts or cleaves this gene at two different locations. So at this location, somewhere here, and in this location somewhere here. So at the end, once we expose this gene to this enzyme, we get three different DNA fragments. So we have DNA fragment one, DNA fragment two, and DNA fragment three. And these fragments all came from this entire gene. Now once we obtain these fragments, we now expose the fragments to the process of gel electrophoresis. | Restriction Map and Gel Electrophoresis.txt |
So we have DNA fragment one, DNA fragment two, and DNA fragment three. And these fragments all came from this entire gene. Now once we obtain these fragments, we now expose the fragments to the process of gel electrophoresis. And what this process does is it ultimately separates these three DNA fragments that came from the gene based on their physical size. So what exactly is gelatrophresis? Well, it's basically the process by which we take our fragments. | Restriction Map and Gel Electrophoresis.txt |
And what this process does is it ultimately separates these three DNA fragments that came from the gene based on their physical size. So what exactly is gelatrophresis? Well, it's basically the process by which we take our fragments. We place them into a special type of porous gel and then we allow those fragments to move through the porous of the gel as a result of an electric field that exists within that gel. So we take the apparatus, we connect the apparatus to a voltage source and that creates an electric potential difference, a voltage difference between the two sides of that electrophoresis setup. And so what happens is, because we connected to our battery source, one end of that plate will have a negative charge. | Restriction Map and Gel Electrophoresis.txt |
We place them into a special type of porous gel and then we allow those fragments to move through the porous of the gel as a result of an electric field that exists within that gel. So we take the apparatus, we connect the apparatus to a voltage source and that creates an electric potential difference, a voltage difference between the two sides of that electrophoresis setup. And so what happens is, because we connected to our battery source, one end of that plate will have a negative charge. So that will be the count node and the other end will have a positive charge that will be the anode. Now remember, DNA contains a negative charge as a result of all those phosphate groups. And so all these DNA fragments that came from the gene will contain negative charge and they will move from the calcio, the negatively charged side, to the anode, the positively charged side. | Restriction Map and Gel Electrophoresis.txt |
So that will be the count node and the other end will have a positive charge that will be the anode. Now remember, DNA contains a negative charge as a result of all those phosphate groups. And so all these DNA fragments that came from the gene will contain negative charge and they will move from the calcio, the negatively charged side, to the anode, the positively charged side. So all these fragments will move along the same direction, but they will move at different speeds. And that's because if we examine the gel inside this setup, that gel is basically a special type of polymer that contains many different pores. And these pores basically contain a certain size to them. | Restriction Map and Gel Electrophoresis.txt |
So all these fragments will move along the same direction, but they will move at different speeds. And that's because if we examine the gel inside this setup, that gel is basically a special type of polymer that contains many different pores. And these pores basically contain a certain size to them. And so the larger DNA fragments, the larger molecules will find it more difficult to move along these pores, while the smaller fragments will find it easier to move along and through these pores because of their smaller physical size and smaller physical weight. So in gel electrophoresis, different fragments are separated on the basis of physical size. The larger molecules are not able to move as quickly as the smaller ones through the pores of that gel. | Restriction Map and Gel Electrophoresis.txt |
And so the larger DNA fragments, the larger molecules will find it more difficult to move along these pores, while the smaller fragments will find it easier to move along and through these pores because of their smaller physical size and smaller physical weight. So in gel electrophoresis, different fragments are separated on the basis of physical size. The larger molecules are not able to move as quickly as the smaller ones through the pores of that gel. Now, since DNA fragments are all negatively charged, they all move along the same direction. They always move from the cathode, the negatively charged side, to the anode, the positively charged side. And this voltage difference is created because this entire structure is connected to a battery source. | Restriction Map and Gel Electrophoresis.txt |
Now, since DNA fragments are all negatively charged, they all move along the same direction. They always move from the cathode, the negatively charged side, to the anode, the positively charged side. And this voltage difference is created because this entire structure is connected to a battery source. So this is what gel electrophoresis is. So the way that we create the restriction map is by exposing this initial gene to many different types of restriction enzymes. For example, in case A, we expose the gene to restriction enzyme number one. | Restriction Map and Gel Electrophoresis.txt |
So this is what gel electrophoresis is. So the way that we create the restriction map is by exposing this initial gene to many different types of restriction enzymes. For example, in case A, we expose the gene to restriction enzyme number one. And we form three different fragments, as shown, that have these different sizes. Now, in case B, we take that same initial gene, but now we expose it to a different restriction enzyme which cuts at different locations along that gene. So now, instead of producing these three fragments, we only produce two fragments because this gene only contains one side, one location where this restriction enzyme number two can actually act on. | Restriction Map and Gel Electrophoresis.txt |
And we form three different fragments, as shown, that have these different sizes. Now, in case B, we take that same initial gene, but now we expose it to a different restriction enzyme which cuts at different locations along that gene. So now, instead of producing these three fragments, we only produce two fragments because this gene only contains one side, one location where this restriction enzyme number two can actually act on. So now we produce fragment four and fragment five. And once again, we expose these two fragments. We place these two fragments into our gel and now we have the separation based on size. | Restriction Map and Gel Electrophoresis.txt |
So now we produce fragment four and fragment five. And once again, we expose these two fragments. We place these two fragments into our gel and now we have the separation based on size. And we can compare this diagram to this diagram and we can use the information obtained to basically create a restriction map. So if we examine the following diagram right over here, we see that for this particular case, this fragment is this fragment here. And notice it is closest to the anode because it is the smallest. | Restriction Map and Gel Electrophoresis.txt |
And we can compare this diagram to this diagram and we can use the information obtained to basically create a restriction map. So if we examine the following diagram right over here, we see that for this particular case, this fragment is this fragment here. And notice it is closest to the anode because it is the smallest. And it is able to move the farthest along and through the porous of the gel. This fragment is basically fragment two. This fragment is fragment three. | Restriction Map and Gel Electrophoresis.txt |
And it is able to move the farthest along and through the porous of the gel. This fragment is basically fragment two. This fragment is fragment three. Now, what about this case? Well, notice that fragment three is almost the same size as fragment four. And so these two will correspond to the same exact position, horizontal position, along the following diagram. | Restriction Map and Gel Electrophoresis.txt |
Now, what about this case? Well, notice that fragment three is almost the same size as fragment four. And so these two will correspond to the same exact position, horizontal position, along the following diagram. Now, this is the largest fragment of these five fragments. And so it will be found highest farthest up along the following plate. So we have the largest fragment. | Restriction Map and Gel Electrophoresis.txt |
Now, this is the largest fragment of these five fragments. And so it will be found highest farthest up along the following plate. So we have the largest fragment. These two fragments are about the same size. Then the next fragment and the smallest fragment, fragment number one. So let's take a marker and let's label these just so we know. | Restriction Map and Gel Electrophoresis.txt |
These two fragments are about the same size. Then the next fragment and the smallest fragment, fragment number one. So let's take a marker and let's label these just so we know. So this is fragment number one, fragment number two, fragment number three, fragment number four and fragment number five. So this is what gel electrophoresis is. Now, when we're, we'll get into biochemistry, we're going to see that we can use gel electrophoresis not only for DNA molecules, but we can also use for proteins. | Restriction Map and Gel Electrophoresis.txt |
Now let's suppose we take the DNA molecule, we expose it to our restriction enzymes and we create these many DNA fragments. And let's say that one of these fragments contains a specific gene that we want to study. The question is how do we identify that specific fragment that is carrying the gene and how do we isolate and separate that fragment to basically study it further? Well, we have to carry out a process known as southern Blotting. In southern Blotting we essentially use gel electrophoresis as we'll see in just a moment to basically identify and isolate a specific DNA fragment of interest. So let's begin with step number one. | Southern and Northern Blotting.txt |
Well, we have to carry out a process known as southern Blotting. In southern Blotting we essentially use gel electrophoresis as we'll see in just a moment to basically identify and isolate a specific DNA fragment of interest. So let's begin with step number one. So we take our double stranded DNA molecule that contains the gene that we want to study. Now we know what the sequence of nucleotides within that gene is before we actually carry out that process and we'll see why that's important in step three. So we take the DNA, the double stranded DNA molecule, we expose it to specific restriction enzymes so that when they clean that DNA molecule one of these fragments will carry that gene of interest. | Southern and Northern Blotting.txt |
So we take our double stranded DNA molecule that contains the gene that we want to study. Now we know what the sequence of nucleotides within that gene is before we actually carry out that process and we'll see why that's important in step three. So we take the DNA, the double stranded DNA molecule, we expose it to specific restriction enzymes so that when they clean that DNA molecule one of these fragments will carry that gene of interest. So let's suppose we break it down into five different fragments and these fragments differ in their size. So we have the largest fragment of fragment A, we have the smallest fragment of fragment E and the fragment in between these fragments in terms of their size is fragment C. And that's the fragment, let's say, that contains the gene that we want to actually study. So fragment C is that DNA fragment, that restriction fragment that we actually want to identify and then separate. | Southern and Northern Blotting.txt |
So let's suppose we break it down into five different fragments and these fragments differ in their size. So we have the largest fragment of fragment A, we have the smallest fragment of fragment E and the fragment in between these fragments in terms of their size is fragment C. And that's the fragment, let's say, that contains the gene that we want to actually study. So fragment C is that DNA fragment, that restriction fragment that we actually want to identify and then separate. So let's move on to step two. So we take these fragments, we essentially place them into a solution that denatures the double helix structure. And so now in our solution we have these single stranded individual DNA molecules and now we take them and place them into a gel electrophoresis seven. | Southern and Northern Blotting.txt |
So let's move on to step two. So we take these fragments, we essentially place them into a solution that denatures the double helix structure. And so now in our solution we have these single stranded individual DNA molecules and now we take them and place them into a gel electrophoresis seven. Now, if the DNA molecule isn't too large we can use the polyacrylamide gel. But if the DNA molecule is very large then we have to use a gel that has larger pore size. So we normally use anguarose gel. | Southern and Northern Blotting.txt |
Now, if the DNA molecule isn't too large we can use the polyacrylamide gel. But if the DNA molecule is very large then we have to use a gel that has larger pore size. So we normally use anguarose gel. So these are the two gels that we can basically use and the one that we use determines or which one we use is determined by the size of that initial DNA molecule. Now, so we take our fragments and we place them into the gel electrofreeze setup. And now the gel electrophoresis basically separates the DNA fragments based on size. | Southern and Northern Blotting.txt |
So these are the two gels that we can basically use and the one that we use determines or which one we use is determined by the size of that initial DNA molecule. Now, so we take our fragments and we place them into the gel electrofreeze setup. And now the gel electrophoresis basically separates the DNA fragments based on size. So the largest fragments, fragment A, will be all the way at the top because it will experience the greatest resistance, while the smallest fragment, fragment e, will be found all the way at the bottom because it does not experience a large resistive force. And once we separate the five fragments based on size, we can then basically transfer that result onto a special polymer sheet that we can use more effectively. And usually we use the nitrocellulose polymer sheet. | Southern and Northern Blotting.txt |
So the largest fragments, fragment A, will be all the way at the top because it will experience the greatest resistance, while the smallest fragment, fragment e, will be found all the way at the bottom because it does not experience a large resistive force. And once we separate the five fragments based on size, we can then basically transfer that result onto a special polymer sheet that we can use more effectively. And usually we use the nitrocellulose polymer sheet. Now, once again, it's important to know that within these regions, these are no longer in their double stranded form, they exist as single stranded DNA molecules. And that leads us directly into step three. So in step two, we essentially separated these fragments based on size. | Southern and Northern Blotting.txt |
Now, once again, it's important to know that within these regions, these are no longer in their double stranded form, they exist as single stranded DNA molecules. And that leads us directly into step three. So in step two, we essentially separated these fragments based on size. The next question is how do we identify which one of these bands contains that gene of interest? So remember in the beginning I said that we have to know what that sequence of nucleotides is in that gene that we want to isolate. And so what we do in step three is we build a DNA molecule, a DNA probe that contains a complementary nucleotide sequence that is complementary to that DNA fragment, the gene that we want to isolate found in fragment C. And when we build it, we radioactively label that DNA probe. | Southern and Northern Blotting.txt |
The next question is how do we identify which one of these bands contains that gene of interest? So remember in the beginning I said that we have to know what that sequence of nucleotides is in that gene that we want to isolate. And so what we do in step three is we build a DNA molecule, a DNA probe that contains a complementary nucleotide sequence that is complementary to that DNA fragment, the gene that we want to isolate found in fragment C. And when we build it, we radioactively label that DNA probe. For example, we use radioactively heavy phosphorus atoms. And what that will allow us to do is in step four, we're going to be able to use x ray autorediography to basically find exactly where that DNA molecule is. So in step three, a specific restriction fragment of interest. | Southern and Northern Blotting.txt |
For example, we use radioactively heavy phosphorus atoms. And what that will allow us to do is in step four, we're going to be able to use x ray autorediography to basically find exactly where that DNA molecule is. So in step three, a specific restriction fragment of interest. So this seed can be detected by creating and adding a radioactively labeled complementary DNA strand to that polymer sheet. Since it is complementary to the gene of interest, it will hybridize with the fragment of interest. So it will basically form a double stranded, form a double stranded helix. | Southern and Northern Blotting.txt |
So this seed can be detected by creating and adding a radioactively labeled complementary DNA strand to that polymer sheet. Since it is complementary to the gene of interest, it will hybridize with the fragment of interest. So it will basically form a double stranded, form a double stranded helix. So, to see exactly what we mean, let's take a look at the following diagram. So in this diagram, it is before we added that DNA probe. And so if we zoom in on this band, band C, we basically get this double stranded DNA molecule has been denatured. | Southern and Northern Blotting.txt |
So, to see exactly what we mean, let's take a look at the following diagram. So in this diagram, it is before we added that DNA probe. And so if we zoom in on this band, band C, we basically get this double stranded DNA molecule has been denatured. And so these two individual single strands exist as single strands. Now, when we add that DNA probe that has been radioactively labeled by, let's say, a heavy phosphorous atom, so what will happen is, because the sequence is complementary to this sequence here, the green radioactively labeled DNA probe will hybridize, will form a double helix structure with that single stranded complementary molecule. And so now this has been radioactively labeled. | Southern and Northern Blotting.txt |
And so these two individual single strands exist as single strands. Now, when we add that DNA probe that has been radioactively labeled by, let's say, a heavy phosphorous atom, so what will happen is, because the sequence is complementary to this sequence here, the green radioactively labeled DNA probe will hybridize, will form a double helix structure with that single stranded complementary molecule. And so now this has been radioactively labeled. And notice this DNA probe will not form the same double helix with any of these other bands because the other bands don't have that complementary sequence. So this molecule is a single stranded DNA fragment of interest that we want to actually detect. And the green molecule is that radioactively labeled DNA probe that contains a nucleotide sequence that is complementary to that restriction fragment above that we essentially want to detect. | Southern and Northern Blotting.txt |
And notice this DNA probe will not form the same double helix with any of these other bands because the other bands don't have that complementary sequence. So this molecule is a single stranded DNA fragment of interest that we want to actually detect. And the green molecule is that radioactively labeled DNA probe that contains a nucleotide sequence that is complementary to that restriction fragment above that we essentially want to detect. And once we carry out step three, then we can use the process of order radiography and that will allow us to pinpoint exactly where that fragment is. And now we know if we go back to this setup, that this band C contains those fragments that we want to isolate. And so we can take out the fragments, remove the other unwanted fragments, and now we have a pure solution that contains only the fragment, only that gene that we were actually interested in the first place. | Southern and Northern Blotting.txt |
And once we carry out step three, then we can use the process of order radiography and that will allow us to pinpoint exactly where that fragment is. And now we know if we go back to this setup, that this band C contains those fragments that we want to isolate. And so we can take out the fragments, remove the other unwanted fragments, and now we have a pure solution that contains only the fragment, only that gene that we were actually interested in the first place. So this process by which we can actually pinpoint, detect and then isolate that DNA fragment of interest by using our DNA probe is known as southern blotting. But we also can repeat the same exact process with RNA molecule. So if we have an RNA molecule that we actually want to isolate, we can use an RNA probe or radioactively RNA probe in the same exact process. | Southern and Northern Blotting.txt |
So this process by which we can actually pinpoint, detect and then isolate that DNA fragment of interest by using our DNA probe is known as southern blotting. But we also can repeat the same exact process with RNA molecule. So if we have an RNA molecule that we actually want to isolate, we can use an RNA probe or radioactively RNA probe in the same exact process. But if we're dealing with RNA, the process is known as north and blotting. So in the same analogous way, we can conduct the same steps to separate and locate RNA fragments. But instead of using the DNA probe, we use a radioactively labeled RNA probe in this process is known as north and Blotting. | Southern and Northern Blotting.txt |
Now, we know to basically calculate, to determine whether reaction is actually exergonic or endergonic, we have to calculate what the gibsfree energy is of that reaction because ultimately it's the gift's free energy value that tells us whether reaction is spontaneous or non spontaneous. Now, the mathematical equation that allows us to actually calculate the magnitude of Gibbs free energy is this equation here. So the gibsfree energy of that particular reaction under those conditions is equal to the Gibbs free energy under standard conditions when the concentration of products and reactants is equal to one molar plus this entire quantity. So 2.33 times r t log q, where r is simply the gas constant, t is the temperature in Kelvin and q is the reaction quotient. And that tells us the ratio of the concentration of products to the reactants. Now, what exactly is the meaning of delta g? | Gibbs Free Energy and Spontaneity.txt |
So 2.33 times r t log q, where r is simply the gas constant, t is the temperature in Kelvin and q is the reaction quotient. And that tells us the ratio of the concentration of products to the reactants. Now, what exactly is the meaning of delta g? Well, delta g tells us the amount of free energy that is produced or used up when a chemical reaction takes place under certain conditions. So if a chemical reaction takes place and it releases gets free energy, that reaction will have a negative delta g value. And such a reaction is said to be spontaneous exergonic. | Gibbs Free Energy and Spontaneity.txt |
Well, delta g tells us the amount of free energy that is produced or used up when a chemical reaction takes place under certain conditions. So if a chemical reaction takes place and it releases gets free energy, that reaction will have a negative delta g value. And such a reaction is said to be spontaneous exergonic. And so this reaction releases useful energy that can be used to power other processes and reactions inside our cells and inside our body. Now, if the delta g is positive, what that means is that particular reaction will be endergonic, non spontaneous, and a positive delta g means we have to input energy for that reaction to actually take place. And in fact, inside our body, we can use exergonic reactions to produce energy and then that energy can be used to carry out undergonic reactions. | Gibbs Free Energy and Spontaneity.txt |
And so this reaction releases useful energy that can be used to power other processes and reactions inside our cells and inside our body. Now, if the delta g is positive, what that means is that particular reaction will be endergonic, non spontaneous, and a positive delta g means we have to input energy for that reaction to actually take place. And in fact, inside our body, we can use exergonic reactions to produce energy and then that energy can be used to carry out undergonic reactions. Now, what about when the delta g is zero? Well, when the delta g is zero, that means our reaction has achieved equilibrium and this q value will become a k, the equilibrium constant. Now, what about the delta g with this degree symbol? | Gibbs Free Energy and Spontaneity.txt |
Now, what about when the delta g is zero? Well, when the delta g is zero, that means our reaction has achieved equilibrium and this q value will become a k, the equilibrium constant. Now, what about the delta g with this degree symbol? What's the meaning of this quantity? Well, this describes the free energy value of the reaction under specific conditions called standard state conditions. And this describes conditions when the concentration of the reactors and products is equal to one molar. | Gibbs Free Energy and Spontaneity.txt |
What's the meaning of this quantity? Well, this describes the free energy value of the reaction under specific conditions called standard state conditions. And this describes conditions when the concentration of the reactors and products is equal to one molar. Now, to see what we mean by that, let's take a look at the following graph. So this energy graph basically contains the y axis, that's the Gibbs free energy. And the x axis is the reaction progress. | Gibbs Free Energy and Spontaneity.txt |
Now, to see what we mean by that, let's take a look at the following graph. So this energy graph basically contains the y axis, that's the Gibbs free energy. And the x axis is the reaction progress. And in this particular example, I used this chemical reaction. So formic acid associates into the conjugate base and produces the H plus ion. Now, let's suppose the concentration of this is one molar, and the concentration of these two products is also one molar. | Gibbs Free Energy and Spontaneity.txt |
And in this particular example, I used this chemical reaction. So formic acid associates into the conjugate base and produces the H plus ion. Now, let's suppose the concentration of this is one molar, and the concentration of these two products is also one molar. So when this is the case, we see that when 1 mol of formic acid at a concentration of one molar transforms into 1 mol of conjugate base and 1 mol of H plus ion. Which are also at a concentration of one molar. Then we see the Delta G between the product and the reactants is given by 21.3 kilojoules or 21,300 Joules of energy. | Gibbs Free Energy and Spontaneity.txt |
So when this is the case, we see that when 1 mol of formic acid at a concentration of one molar transforms into 1 mol of conjugate base and 1 mol of H plus ion. Which are also at a concentration of one molar. Then we see the Delta G between the product and the reactants is given by 21.3 kilojoules or 21,300 Joules of energy. Now, because the energy, the free energy of the products is higher than the free energy of the reactants, that means this reaction is andergonic. And so we need to input 21.3 kilojoules of energy to actually drive this reaction in the forward direction. So this reaction, as described here understanding conditions, is andergonic it's non spontaneous, it's reactant favorite. | Gibbs Free Energy and Spontaneity.txt |
Now, because the energy, the free energy of the products is higher than the free energy of the reactants, that means this reaction is andergonic. And so we need to input 21.3 kilojoules of energy to actually drive this reaction in the forward direction. So this reaction, as described here understanding conditions, is andergonic it's non spontaneous, it's reactant favorite. And this is in accordance with the fact that formic acid is a weak acid and will not associate to a very large extent. Now, just because the Delta G degree symbol the Delta G under standard state conditions is positive for these conditions, does not mean the Delta G will be positive under some other conditions. In fact, by changing the Q value, by changing the concentrations of the reactants and products, we can ultimately transform this endergonic reaction into an exergonic reaction. | Gibbs Free Energy and Spontaneity.txt |
And this is in accordance with the fact that formic acid is a weak acid and will not associate to a very large extent. Now, just because the Delta G degree symbol the Delta G under standard state conditions is positive for these conditions, does not mean the Delta G will be positive under some other conditions. In fact, by changing the Q value, by changing the concentrations of the reactants and products, we can ultimately transform this endergonic reaction into an exergonic reaction. And this is a very important concept because it is continually used inside our body. Our body changes the concentrations of energonic reactions to basically transform them into exergonic reactions. Now, if we look at the following equation, this equation tells us exactly that. | Gibbs Free Energy and Spontaneity.txt |
And this is a very important concept because it is continually used inside our body. Our body changes the concentrations of energonic reactions to basically transform them into exergonic reactions. Now, if we look at the following equation, this equation tells us exactly that. So what the equation tells us is if this quantity is positive, then this doesn't necessarily have to be positive. If this is positive, but this entire term is more negative than this is positive as a result of this Q value, then a positive quantity plus a negative value that is greater than this in magnitude will give us a Delta G that is negative. And it's this Delta G, it's the sign of this Delta G, not this one, that ultimately dictates whether reaction is actually product favored or reactant favored. | Gibbs Free Energy and Spontaneity.txt |
So what the equation tells us is if this quantity is positive, then this doesn't necessarily have to be positive. If this is positive, but this entire term is more negative than this is positive as a result of this Q value, then a positive quantity plus a negative value that is greater than this in magnitude will give us a Delta G that is negative. And it's this Delta G, it's the sign of this Delta G, not this one, that ultimately dictates whether reaction is actually product favored or reactant favored. And to see what we mean by that, let's carry out the following calculation. So, in this particular case, we know that Delta G standard state condition is equal to 21.3 kilojoules. Now, the question is what exactly should the Q value be for this Delta G to actually be negative and for our reaction to be spontaneous product favorite. | Gibbs Free Energy and Spontaneity.txt |
And to see what we mean by that, let's carry out the following calculation. So, in this particular case, we know that Delta G standard state condition is equal to 21.3 kilojoules. Now, the question is what exactly should the Q value be for this Delta G to actually be negative and for our reaction to be spontaneous product favorite. And the way that we're going to solve this problem is by basically using some type of negative value for this Delta G. So let's suppose Delta G is any negative value for, so let's suppose it's negative five kilojoules. So this quantity is negative five kilojoules and this quantity is positive 21.3 kilojoules. Now, because the gas constant R is given to us in Joules, so 8.3 114 Joules per kelvin times mole, let's transform these quantities into Joules. | Gibbs Free Energy and Spontaneity.txt |
And the way that we're going to solve this problem is by basically using some type of negative value for this Delta G. So let's suppose Delta G is any negative value for, so let's suppose it's negative five kilojoules. So this quantity is negative five kilojoules and this quantity is positive 21.3 kilojoules. Now, because the gas constant R is given to us in Joules, so 8.3 114 Joules per kelvin times mole, let's transform these quantities into Joules. So this quantity is equivalent to 21,300 Joules and that's a positive value. While this quantity, we said just a moment ago we're going to use negative five kilojoules, or equivalently negative 5000 Joules. Now, the goal is to ultimately calculate what the Q value has to be, what the ratio of the concentrations of the products to the reactants has to be for the reaction to actually be product favored, for this to be negative 5000 on negative value. | Gibbs Free Energy and Spontaneity.txt |
So this quantity is equivalent to 21,300 Joules and that's a positive value. While this quantity, we said just a moment ago we're going to use negative five kilojoules, or equivalently negative 5000 Joules. Now, the goal is to ultimately calculate what the Q value has to be, what the ratio of the concentrations of the products to the reactants has to be for the reaction to actually be product favored, for this to be negative 5000 on negative value. Now, notice we could have also used negative five joules or negative 1 million joules. Basically any negative value here works because any negative value means this reaction will be spontaneous under that Q situation, under that concentration of products and reactants. So if we take this equation now and solve for a log of Q, we get that log of Q is equal to so this term is brought to this side. | Gibbs Free Energy and Spontaneity.txt |
Now, notice we could have also used negative five joules or negative 1 million joules. Basically any negative value here works because any negative value means this reaction will be spontaneous under that Q situation, under that concentration of products and reactants. So if we take this equation now and solve for a log of Q, we get that log of Q is equal to so this term is brought to this side. So it's this minus this on the top. And then we divide by this quantity. So 2.33. | Gibbs Free Energy and Spontaneity.txt |
So it's this minus this on the top. And then we divide by this quantity. So 2.33. Then the gas constant is 8.3 114 joules per mole times Kelvin. And the temperature we're going to assume is, let's say 25 degrees Celsius, so equivalently 298 Kelvins. Now, if we solve for Q, we get that Q is equal to ten to the power of this ratio. | Gibbs Free Energy and Spontaneity.txt |
Then the gas constant is 8.3 114 joules per mole times Kelvin. And the temperature we're going to assume is, let's say 25 degrees Celsius, so equivalently 298 Kelvins. Now, if we solve for Q, we get that Q is equal to ten to the power of this ratio. Now this divided by this gives us negative 4.61. And so if we carry out this calculation, raised ten to the power of negative 4.61, we get about 2.45 times ten to negative five. Now, what this means is when the Q value, when this quantity, when the ratio of the concentration of the product and the reactants is equal to 0.245, the reaction, this reaction here will actually be exergonic, it will be spontaneous and it will be product favored. | Gibbs Free Energy and Spontaneity.txt |
Now this divided by this gives us negative 4.61. And so if we carry out this calculation, raised ten to the power of negative 4.61, we get about 2.45 times ten to negative five. Now, what this means is when the Q value, when this quantity, when the ratio of the concentration of the product and the reactants is equal to 0.245, the reaction, this reaction here will actually be exergonic, it will be spontaneous and it will be product favored. So what we basically show is even though this reaction is undergodonic under standard conditions, when the concentrations of these are equal, if we change the concentrations around, we can actually transform that endergonic non spontaneous reaction into an exergonic spontaneous reaction, as can be seen in the following example where we use the delta g on negative quantity. So ultimately it's the delta g that determines whether our reaction under those concentration conditions and that temperature value is actually spontaneous or not. This doesn't necessarily have to be negative or positive. | Gibbs Free Energy and Spontaneity.txt |
Within the developing fetus. The organ that is involved in exchanging gas between the mother and the fetus is called the placenta. Now, the placenta has other functions as well, but in this lecture we're going to focus primarily on its function in gas exchange. So let's begin by actually looking at the structure of our placenta. So this is a diagram of the placement placenta. So we have the umbilical cord shown here that contains two types of blood vessels. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
So let's begin by actually looking at the structure of our placenta. So this is a diagram of the placement placenta. So we have the umbilical cord shown here that contains two types of blood vessels. We have the umbilical vein shown in red and we have umbilical arteries shown in blue. So the umbilical arteries carry deoxygenated blood that contains carbon dioxide from the organs and tissues of that fetus and to the placenta itself. And it carries them to these Corianic villi, these extensions of the Coriane known as the corionic villi. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
We have the umbilical vein shown in red and we have umbilical arteries shown in blue. So the umbilical arteries carry deoxygenated blood that contains carbon dioxide from the organs and tissues of that fetus and to the placenta itself. And it carries them to these Corianic villi, these extensions of the Coriane known as the corionic villi. And within the Corianic villi, we have the tiny blood capillaries that belong to the circulatory system of that fetus. Now, these entire Corianic villi are found inside a pool of maternal blood. And that pool of maternal blood essentially oozes out of these maternal blood vessels that are found in close proximity. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
And within the Corianic villi, we have the tiny blood capillaries that belong to the circulatory system of that fetus. Now, these entire Corianic villi are found inside a pool of maternal blood. And that pool of maternal blood essentially oozes out of these maternal blood vessels that are found in close proximity. So remember, when the placenta was actually developed, the Corian released these digestive enzymes that digested tiny holes inside these maternal blood vessels. And those holes essentially allow the blood to actually leak out. So the way that the exchange takes place is within the maternal blood. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
So remember, when the placenta was actually developed, the Corian released these digestive enzymes that digested tiny holes inside these maternal blood vessels. And those holes essentially allow the blood to actually leak out. So the way that the exchange takes place is within the maternal blood. Within the pool of maternal blood we have oxygen. And oxygen moves down its concentration gradient from the pool of blood and into the capillaries of that fetus. At the same time, carbon dioxide is deposited out of the capillaries of that fetus and into the pool of blood and eventually picked up by the maternal blood veins. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
Within the pool of maternal blood we have oxygen. And oxygen moves down its concentration gradient from the pool of blood and into the capillaries of that fetus. At the same time, carbon dioxide is deposited out of the capillaries of that fetus and into the pool of blood and eventually picked up by the maternal blood veins. And that carries the carbon dioxide to the lungs of that mother and the lungs expel the carbon dioxide to the rest of that environment. At the same time, when the lungs inhale, they bring in oxygen. And that oxygen is ultimately brought into this pooling area of that maternal blood. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
And that carries the carbon dioxide to the lungs of that mother and the lungs expel the carbon dioxide to the rest of that environment. At the same time, when the lungs inhale, they bring in oxygen. And that oxygen is ultimately brought into this pooling area of that maternal blood. Now, when the oxygen is picked up, it is picked up by these blood vessels. And then the blood vessels connect to the umbilical vein and umbilical vein. This blood vessel, shown in red, actually carries the oxygenated and nutrient filled blood to the organs, tissues and structures found within that developing fetus. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
Now, when the oxygen is picked up, it is picked up by these blood vessels. And then the blood vessels connect to the umbilical vein and umbilical vein. This blood vessel, shown in red, actually carries the oxygenated and nutrient filled blood to the organs, tissues and structures found within that developing fetus. So this is how gas exchange actually takes place. Now, the question we want to ask in this lecture is what exactly makes the placenta effective and efficient in actually exchanging that oxygen and what allows it to exchange that oxygen, carbon dioxide, in the right direction. So remember, we want the placenta not only to exchange the gases quickly and efficiently, but we also want to exchange the gasses in the right direction. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
So this is how gas exchange actually takes place. Now, the question we want to ask in this lecture is what exactly makes the placenta effective and efficient in actually exchanging that oxygen and what allows it to exchange that oxygen, carbon dioxide, in the right direction. So remember, we want the placenta not only to exchange the gases quickly and efficiently, but we also want to exchange the gasses in the right direction. So we must make sure that oxygen always travels into that fetus and carbon dioxide is always removed from that fetus and moves into the blood capillaries and the blood system of the mother. So there are three factors that affect the efficiency of that placenta, and one of them is the type of hemoglobin molecule that is found inside the blood of that fetus. So recall that oxygen is actually a nonpolar molecule. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
So we must make sure that oxygen always travels into that fetus and carbon dioxide is always removed from that fetus and moves into the blood capillaries and the blood system of the mother. So there are three factors that affect the efficiency of that placenta, and one of them is the type of hemoglobin molecule that is found inside the blood of that fetus. So recall that oxygen is actually a nonpolar molecule. And what that means is it cannot readily dissolve in the blood plasma. And so it requires a special type of protein carrier to carry it from point A to point B. And this type of protein is known as hemoglobin. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
And what that means is it cannot readily dissolve in the blood plasma. And so it requires a special type of protein carrier to carry it from point A to point B. And this type of protein is known as hemoglobin. Now, the type of hemoglobin molecule found inside adults is different than the type of hemoglobin that is found inside the fetus. Before we actually see why this is the case, let's discuss what the difference is between the adult and the fetal hemoglobin. So, in adults, we know that the hemoglobin consists of four subunits. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
Now, the type of hemoglobin molecule found inside adults is different than the type of hemoglobin that is found inside the fetus. Before we actually see why this is the case, let's discuss what the difference is between the adult and the fetal hemoglobin. So, in adults, we know that the hemoglobin consists of four subunits. Two of these subunits are alpha subunits, and the other two subunits are beta subunits. So we have alpha one and alpha two that combines with beta one and beta two to form a protein tetrimer that we call the dull hemoglobin. So this is what it looks like. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
Two of these subunits are alpha subunits, and the other two subunits are beta subunits. So we have alpha one and alpha two that combines with beta one and beta two to form a protein tetrimer that we call the dull hemoglobin. So this is what it looks like. We have alpha one, alpha two shown in green, and we have beta one and beta two shown in orange. Now, when we form the adult hemoglobin, the adult hemoglobin actually contains a cavity inside a space that is capable of binding a molecule called two three BPG. Now, what exactly is two three BPG? | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
We have alpha one, alpha two shown in green, and we have beta one and beta two shown in orange. Now, when we form the adult hemoglobin, the adult hemoglobin actually contains a cavity inside a space that is capable of binding a molecule called two three BPG. Now, what exactly is two three BPG? Well, two three BPG is a molecule that is a byproduct of cellular respiration. So when cell respiration takes place inside the cells of the adult individual, they produce two three BPG. And two three BPG can actually bind into that cavity into the space that is found in the adult hemoglobin. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
Well, two three BPG is a molecule that is a byproduct of cellular respiration. So when cell respiration takes place inside the cells of the adult individual, they produce two three BPG. And two three BPG can actually bind into that cavity into the space that is found in the adult hemoglobin. Now, as soon as the binding takes place, when the two three BPG binds into that space inside the adult hemoglobin, it creates a change in the structure of the adult hemoglobin. And what that does is it decreases the adult hemoglobin's ability to actually bind to oxygen. It lowers its affinity for oxygen. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
Now, as soon as the binding takes place, when the two three BPG binds into that space inside the adult hemoglobin, it creates a change in the structure of the adult hemoglobin. And what that does is it decreases the adult hemoglobin's ability to actually bind to oxygen. It lowers its affinity for oxygen. So when the binding takes place, that adult hemoglobin is much less likely to actually bind oxygen and carry oxygen from point A to point B. Now, what about the fetal hemoglobin? Well, just like the delt hemoglobin, the fetal hemoglobin also consists of four subunits. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
So when the binding takes place, that adult hemoglobin is much less likely to actually bind oxygen and carry oxygen from point A to point B. Now, what about the fetal hemoglobin? Well, just like the delt hemoglobin, the fetal hemoglobin also consists of four subunits. It contains alpha one and alpha two, as shown in the following diagram. But it doesn't contain beta one and beta two. Instead, it contains a slightly different two subunits gamma one and gamma two. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
It contains alpha one and alpha two, as shown in the following diagram. But it doesn't contain beta one and beta two. Instead, it contains a slightly different two subunits gamma one and gamma two. And when these four subunits create the tetrimer fetal hemoglobin, notice we no longer have that space inside the hemoglobin that can accommodate the two three BPG. And so, unlike the Dull hemoglobin, the fetal hemoglobin in the presence of two three BPG does not actually bind to two three BPG. And what that means is if we compare the affinity of these two hemoglobin molecules in the presence of the same concentration of two three BPG, we see that because the fetal hemoglobin doesn't actually bind the two, three BPG, that means its affinity for oxygen will be much higher than the affinity for oxygen of adult hemoglobin. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
And when these four subunits create the tetrimer fetal hemoglobin, notice we no longer have that space inside the hemoglobin that can accommodate the two three BPG. And so, unlike the Dull hemoglobin, the fetal hemoglobin in the presence of two three BPG does not actually bind to two three BPG. And what that means is if we compare the affinity of these two hemoglobin molecules in the presence of the same concentration of two three BPG, we see that because the fetal hemoglobin doesn't actually bind the two, three BPG, that means its affinity for oxygen will be much higher than the affinity for oxygen of adult hemoglobin. And if we plot this curve on the x y axis, where the x axis is the partial pressure of oxygen given in millimeters of mercury, and the y axis is the percent saturation of that hemoglobin, we get the following curve. So the blue curve is the curve that describes the adult hemoglobin, while the red curve describes the fetal hemoglobin. And notice at the same partial pressure, let's say at 40 degrees partial pressure of oxygen, the adult hemoglobin has much less saturation than the fetal hemoglobin does. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
And if we plot this curve on the x y axis, where the x axis is the partial pressure of oxygen given in millimeters of mercury, and the y axis is the percent saturation of that hemoglobin, we get the following curve. So the blue curve is the curve that describes the adult hemoglobin, while the red curve describes the fetal hemoglobin. And notice at the same partial pressure, let's say at 40 degrees partial pressure of oxygen, the adult hemoglobin has much less saturation than the fetal hemoglobin does. And that's because a fetal hemoglobin does not actually bind to two, three BPG. And so it is much more likely to actually attract other oxygen molecules and bind to those oxygen molecules. So we see that the maternal red blood cells have hemoglobin, the adult hemoglobin that binds oxygen much less readily than the fetal red blood cells that contain the fetal hemoglobin. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
And that's because a fetal hemoglobin does not actually bind to two, three BPG. And so it is much more likely to actually attract other oxygen molecules and bind to those oxygen molecules. So we see that the maternal red blood cells have hemoglobin, the adult hemoglobin that binds oxygen much less readily than the fetal red blood cells that contain the fetal hemoglobin. And as a result, the oxygen will be much more likely to actually move from the blood of that mother and into the blood of that fetus that contains that fetal hemoglobin. Now, aside from this, there are two other factors that also facilitate the function of the placenta, facilitate the gas exchange process. So the movement of oxygen from the mother to the fetus can be facilitated by three factors. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
And as a result, the oxygen will be much more likely to actually move from the blood of that mother and into the blood of that fetus that contains that fetal hemoglobin. Now, aside from this, there are two other factors that also facilitate the function of the placenta, facilitate the gas exchange process. So the movement of oxygen from the mother to the fetus can be facilitated by three factors. So one of them is higher affinity of fetal hemoglobin for oxygen than the adult hemoglobin. The other is the fact that inside the blood of the mother, we have a higher concentration of oxygen than inside these capillaries of that fetus. And so because of this difference in concentration, because the concentration of oxygen is naturally higher inside the blood of that mother than inside the blood of that fetus, oxygen will tend to basically move down its concentration gradient, down its pressure gradient from the mother and to that fetus. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
So one of them is higher affinity of fetal hemoglobin for oxygen than the adult hemoglobin. The other is the fact that inside the blood of the mother, we have a higher concentration of oxygen than inside these capillaries of that fetus. And so because of this difference in concentration, because the concentration of oxygen is naturally higher inside the blood of that mother than inside the blood of that fetus, oxygen will tend to basically move down its concentration gradient, down its pressure gradient from the mother and to that fetus. So the final fact that that facilitates the diffusion of oxygen across our placenta is something called the double bore effect. So let's recall what a bore effect is. So, the bore effect is basically the ability of carbon dioxide to affect the affinity of hemoglobin. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
So the final fact that that facilitates the diffusion of oxygen across our placenta is something called the double bore effect. So let's recall what a bore effect is. So, the bore effect is basically the ability of carbon dioxide to affect the affinity of hemoglobin. So the more carbon dioxide we have in the blood, the less likely that hemoglobin will actually bind onto that oxygen. And conversely, the less CO2 we have in the blood, the more likely our oxygen, our hemoglobin, will actually bind to oxygen. So what exactly do we mean by double bore effect? | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
So the more carbon dioxide we have in the blood, the less likely that hemoglobin will actually bind onto that oxygen. And conversely, the less CO2 we have in the blood, the more likely our oxygen, our hemoglobin, will actually bind to oxygen. So what exactly do we mean by double bore effect? Well, let's take a look at the following diagram to see what the double bore effect is. So, let's suppose that this purple line is basically our placental membrane. And our gas exchange takes place across the placental membrane, which is basically this coryonic membrane shown right here in purple. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
Well, let's take a look at the following diagram to see what the double bore effect is. So, let's suppose that this purple line is basically our placental membrane. And our gas exchange takes place across the placental membrane, which is basically this coryonic membrane shown right here in purple. So this is the side of the mother. This is the side of the fetus. So what happens is carbon dioxide moves down its concentration gradient from this side from the fetus's side to the mother's side. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
So this is the side of the mother. This is the side of the fetus. So what happens is carbon dioxide moves down its concentration gradient from this side from the fetus's side to the mother's side. Now, as it moves this way, what happens is the concentration of the carbon, the oxide, begins to increase within the side of the mother. And by increasing the CO2 concentration, that makes the hemoglobin much more likely to actually release the oxygen. And once oxygen is released, we have the bore effect. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
Now, as it moves this way, what happens is the concentration of the carbon, the oxide, begins to increase within the side of the mother. And by increasing the CO2 concentration, that makes the hemoglobin much more likely to actually release the oxygen. And once oxygen is released, we have the bore effect. So that is the bore effect. So as a result of the release of carbon dioxide onto the mother's side we have the bore effect take place on the mother's side. The carbon dioxide affects the affinity of hemoglobin, decreases its affinity for hemoglobin, decreases hemoglobin's affinity for oxygen. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
So that is the bore effect. So as a result of the release of carbon dioxide onto the mother's side we have the bore effect take place on the mother's side. The carbon dioxide affects the affinity of hemoglobin, decreases its affinity for hemoglobin, decreases hemoglobin's affinity for oxygen. Oxygen is released, and then it moves into the side of our fetus. Now, at the same time that carbon dioxide concentration on the mother's side is increasing the carbon dioxide on the fetus side is decreasing in concentration because this is moving this way. Now, when we decrease the concentration of carbon dioxide that means less of the CO2 can actually affect that hemoglobin on the side of the fetus. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
Oxygen is released, and then it moves into the side of our fetus. Now, at the same time that carbon dioxide concentration on the mother's side is increasing the carbon dioxide on the fetus side is decreasing in concentration because this is moving this way. Now, when we decrease the concentration of carbon dioxide that means less of the CO2 can actually affect that hemoglobin on the side of the fetus. And so we also see a bore effect taking place on this side. So less CO2 means more of that hemoglobin will be able to buy to more of that oxygen that is coming in. And so this is the double bore effect that takes place not only on the mother's side but also on the side of the fetus. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
And so we also see a bore effect taking place on this side. So less CO2 means more of that hemoglobin will be able to buy to more of that oxygen that is coming in. And so this is the double bore effect that takes place not only on the mother's side but also on the side of the fetus. So these three factors actually facilitate the exchange of gases inside our placenta. So we have the the ability of that fetal hemoglobin to actually bind to oxygen much more readily than the adult hemoglobin. That is factor number one. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
So these three factors actually facilitate the exchange of gases inside our placenta. So we have the the ability of that fetal hemoglobin to actually bind to oxygen much more readily than the adult hemoglobin. That is factor number one. Factor number two is the fact that inside the mother we have a higher amount of oxygen than inside the fetus. And so it moves down its concentration and pressure gradient from the mother's side to the fetus side. And finally, we also have the double bore effect. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
Factor number two is the fact that inside the mother we have a higher amount of oxygen than inside the fetus. And so it moves down its concentration and pressure gradient from the mother's side to the fetus side. And finally, we also have the double bore effect. So the fact that carbon dioxide is being pumped is being expelled into the blood of that mother causes the hemoglobin inside this mother's area to basically decrease its affinity for oxygen. And because of that, more oxygen is expelled, is released, and then the oxygen moves into the capillaries of the Corianic villi. And as the concentration of carbon dioxide decreases within the capillaries of that fetus we have less CO2 that can affect hemoglobin's ability to bind to oxygen. | Gas Exchange in Placenta, Fetal Hemoglobin and Double Bohr Effect .txt |
We have many different types of biological processes that are catalyzed by enzymes. And what these enzymes do is they speed up the rates of these biological reactions. Now, because enzymes affect the rates, to actually understand how enzymes work, we have to understand the rates of these enzymecatalyzed reactions. And in fact, enzyme kinetics is the study of the rates of these enzyme catalyzed reactions that take place inside our body. Now, in the next lecture we're going to begin our study of enzyme kinetics. But in this lecture we're going to remember some basic information about how to actually represent and express the rates of chemical reactions. | Effect of Enzymes on Rate Law and Rate Constant .txt |
And in fact, enzyme kinetics is the study of the rates of these enzyme catalyzed reactions that take place inside our body. Now, in the next lecture we're going to begin our study of enzyme kinetics. But in this lecture we're going to remember some basic information about how to actually represent and express the rates of chemical reactions. We're going to remember what the rate law is and what the rate constant is and how enzymes affect these two quantities. And we're also going to remember what the order of reaction is. So let's begin with the following hypothetical chemical reaction. | Effect of Enzymes on Rate Law and Rate Constant .txt |
We're going to remember what the rate law is and what the rate constant is and how enzymes affect these two quantities. And we're also going to remember what the order of reaction is. So let's begin with the following hypothetical chemical reaction. We have reactants A and B that are being consumed and C and D, the products are being formed. Now because we have a one to one to one to 1 mol ratio, because the coefficients are one to one to one to one and because these are being consumed and these are being produced at the same time these are being consumed. These four equations basically describe the rates of these individual reactants. | Effect of Enzymes on Rate Law and Rate Constant .txt |
We have reactants A and B that are being consumed and C and D, the products are being formed. Now because we have a one to one to one to 1 mol ratio, because the coefficients are one to one to one to one and because these are being consumed and these are being produced at the same time these are being consumed. These four equations basically describe the rates of these individual reactants. So as the reaction is progressing from the reactant side to the product side, a is being consumed. And that's why the rate of A is negative and the rate of A is simply given by the change in the concentration of A with respect to some time interval and likewise B is also being consumed. So the rate of B is negative and it's given by delta the change in concentration of B with respect to the time and likewise over the same time interval. | Effect of Enzymes on Rate Law and Rate Constant .txt |
So as the reaction is progressing from the reactant side to the product side, a is being consumed. And that's why the rate of A is negative and the rate of A is simply given by the change in the concentration of A with respect to some time interval and likewise B is also being consumed. So the rate of B is negative and it's given by delta the change in concentration of B with respect to the time and likewise over the same time interval. These are the rates of C and D. So the rate of C is the change in C with respect to T and the rate of D is change in D with respect to T. Now, these equations aren't very useful. What we actually want to be able to express is the entire rate of that entire equation as a whole. And this is where the rate law and the rate constant comes into play. | Effect of Enzymes on Rate Law and Rate Constant .txt |
These are the rates of C and D. So the rate of C is the change in C with respect to T and the rate of D is change in D with respect to T. Now, these equations aren't very useful. What we actually want to be able to express is the entire rate of that entire equation as a whole. And this is where the rate law and the rate constant comes into play. The rate law basically uses the rate constant as well as the concentrations of reactants to basically express mathematically what the rate of that chemical reaction is as a whole. So let's suppose we have the following elementary reaction. So what do we mean by an elementary reaction? | Effect of Enzymes on Rate Law and Rate Constant .txt |
The rate law basically uses the rate constant as well as the concentrations of reactants to basically express mathematically what the rate of that chemical reaction is as a whole. So let's suppose we have the following elementary reaction. So what do we mean by an elementary reaction? Well, recall from general chemistry, an elementary reaction is a reaction that takes place in a single step. And the important thing about elementary reactions that you have to remember is in any elementary reaction we can use the coefficient of that reactant to basically determine what the order of that reactant is within that rate law. So we can use the coefficient in front of the reactant to basically tell us what the exponent value is of that particular reactant in that rate law. | Effect of Enzymes on Rate Law and Rate Constant .txt |
Well, recall from general chemistry, an elementary reaction is a reaction that takes place in a single step. And the important thing about elementary reactions that you have to remember is in any elementary reaction we can use the coefficient of that reactant to basically determine what the order of that reactant is within that rate law. So we can use the coefficient in front of the reactant to basically tell us what the exponent value is of that particular reactant in that rate law. So the rate law of the above elementary chemical reaction is usually described by using the rate law and the rate will depends on the rate constant k and usually depends on the concentration of the reactants. So in this lecture we're only going to look at elementary reactions. But you have to remember that if we're dealing with a multistep complicated reaction, then we cannot simply use the coefficients. | Effect of Enzymes on Rate Law and Rate Constant .txt |
So the rate law of the above elementary chemical reaction is usually described by using the rate law and the rate will depends on the rate constant k and usually depends on the concentration of the reactants. So in this lecture we're only going to look at elementary reactions. But you have to remember that if we're dealing with a multistep complicated reaction, then we cannot simply use the coefficients. In that case, we have to determine the rate law experimentally. But if we have a single step reaction, then we can use the coefficients to calculate the rate law. So in this particular case, going from A to B, a is the reactant and B is the product. | Effect of Enzymes on Rate Law and Rate Constant .txt |