text
stringlengths 98
1.39k
| title
stringlengths 10
73
|
|---|---|
So the blood vessels that carry the blood to our cardiac and skeletal muscle increase in size. They dilate. But the blood vessels that carry the blood to our digestive tract basically decrease in size. They constrict because our rate of activity decreases inside the gastrointestinal system. So now that we know what the job and function of the sympathetic nervous system is let's actually discuss the pathway of the electrical signal along the neurons inside the sympathetic nervous system. So we have two neurons in our pathway. | Autonomic Nervous System .txt |
They constrict because our rate of activity decreases inside the gastrointestinal system. So now that we know what the job and function of the sympathetic nervous system is let's actually discuss the pathway of the electrical signal along the neurons inside the sympathetic nervous system. So we have two neurons in our pathway. The first neuron is known as our pre ganglionic neuron and the second neuron is known as the post ganglionic neuron. Now, all pre ganglionic neurons in a sympathetic nervous system begin in the spinal cord of our body. So the cell, body and the dendrites of the pre ganglionic neuron are found in our spinal cord when they actually exit. | Autonomic Nervous System .txt |
The first neuron is known as our pre ganglionic neuron and the second neuron is known as the post ganglionic neuron. Now, all pre ganglionic neurons in a sympathetic nervous system begin in the spinal cord of our body. So the cell, body and the dendrites of the pre ganglionic neuron are found in our spinal cord when they actually exit. When the axon exits our spinal cord, it always exits from the front side, known as our ventral side. And the axon of the pre ganglionic neuron is relatively short compared to our axon of the post ganglionic neuron. Now, at the first synapse between our pre ganglionic and the post ganglionic cell of the sympathetic nervous system we use acetylcholine as our neurotransmitter to pass that signal from our pre to our post ganglionic cell. | Autonomic Nervous System .txt |
When the axon exits our spinal cord, it always exits from the front side, known as our ventral side. And the axon of the pre ganglionic neuron is relatively short compared to our axon of the post ganglionic neuron. Now, at the first synapse between our pre ganglionic and the post ganglionic cell of the sympathetic nervous system we use acetylcholine as our neurotransmitter to pass that signal from our pre to our post ganglionic cell. Now, when the action potential is carried all the way to the exxon terminal of the post ganglionic cell at the synapse between our exxon terminal the post ganglionic cell and the cell of our effector organ. In this case, we use a different neurotransmitter. We either use Epinephrine or we use Norepinephrine. | Autonomic Nervous System .txt |
Now, when the action potential is carried all the way to the exxon terminal of the post ganglionic cell at the synapse between our exxon terminal the post ganglionic cell and the cell of our effector organ. In this case, we use a different neurotransmitter. We either use Epinephrine or we use Norepinephrine. So once again, in the case of the sympathetic nervous system, every single pre ganglionic cell begins in our spinal cord and we'll see this is not the case in the parasympathetic system. Now, there is an exception to this rule. So inside the sympathetic nervous system, we usually have two of these neurons. | Autonomic Nervous System .txt |
So once again, in the case of the sympathetic nervous system, every single pre ganglionic cell begins in our spinal cord and we'll see this is not the case in the parasympathetic system. Now, there is an exception to this rule. So inside the sympathetic nervous system, we usually have two of these neurons. We have a pre and opposed ganglionic neuron. But there is one exception. The electrical signal that is carried from the spinal cord to our adrenal medulla is carried by only a single neuron, by one pre ganglionic neuron. | Autonomic Nervous System .txt |
We have a pre and opposed ganglionic neuron. But there is one exception. The electrical signal that is carried from the spinal cord to our adrenal medulla is carried by only a single neuron, by one pre ganglionic neuron. So the pre ganglionic neuron basically carries that electric signal all the way to our adrenal medulla without using the pose ganglionic neuron. And our neurotransmitter in that case is still acetylcholine. So now let's move on to our parasympathetic nervous system. | Autonomic Nervous System .txt |
So the pre ganglionic neuron basically carries that electric signal all the way to our adrenal medulla without using the pose ganglionic neuron. And our neurotransmitter in that case is still acetylcholine. So now let's move on to our parasympathetic nervous system. So in many different ways, the parasympathetic nervous system basically reverses these effects. So let's suppose we just ate and we basically ate. We sit down and we begin watching TV. | Autonomic Nervous System .txt |
So in many different ways, the parasympathetic nervous system basically reverses these effects. So let's suppose we just ate and we basically ate. We sit down and we begin watching TV. So what begins to take place? So as we're watching our television, we're not basically using our muscles as much. So that means we do not have to worry about producing ATP to move our muscles, to contract our muscles. | Autonomic Nervous System .txt |
So what begins to take place? So as we're watching our television, we're not basically using our muscles as much. So that means we do not have to worry about producing ATP to move our muscles, to contract our muscles. So what the parasympathetic system does is it basically decreases the rate of the heart and it decreases our respiration rate, basically the opposite of what the sympathetic nervous system did. Because we're not sweating as much, we don't have to worry about sweating as in this case. So our sweating basically drops at the same time because we just ate. | Autonomic Nervous System .txt |
So what the parasympathetic system does is it basically decreases the rate of the heart and it decreases our respiration rate, basically the opposite of what the sympathetic nervous system did. Because we're not sweating as much, we don't have to worry about sweating as in this case. So our sweating basically drops at the same time because we just ate. We have to digest our food and we have to absorb our food, the nutrients inside the small intestine. So what happens is the digestion rate basically increases. Our excretory system is working much more than before and we're no longer inhibiting, we're inducing our peristalis so that we can actually move that food along our small intestine. | Autonomic Nervous System .txt |
We have to digest our food and we have to absorb our food, the nutrients inside the small intestine. So what happens is the digestion rate basically increases. Our excretory system is working much more than before and we're no longer inhibiting, we're inducing our peristalis so that we can actually move that food along our small intestine. So the parasympathetic division of our autonomic nervous system is responsible for the rest and digest activities. This means it increases the flow of blood to our digestive organs and excretory system. So that means the blood vessels carrying blood to our digestive organs increases in size, they dilate, while our blood vessels that carry our blood to our skeletal tissue decreases in size. | Autonomic Nervous System .txt |
So the parasympathetic division of our autonomic nervous system is responsible for the rest and digest activities. This means it increases the flow of blood to our digestive organs and excretory system. So that means the blood vessels carrying blood to our digestive organs increases in size, they dilate, while our blood vessels that carry our blood to our skeletal tissue decreases in size. And so we have a decrease in blood flow because we don't have to worry about moving our arms or legs. We're not actually running, we're sitting down and we're watching television. So this is what the parasympathetic nervous system does. | Autonomic Nervous System .txt |
And so we have a decrease in blood flow because we don't have to worry about moving our arms or legs. We're not actually running, we're sitting down and we're watching television. So this is what the parasympathetic nervous system does. Now, in the same exact way that we discussed our pathway of the electrical signal, let's discuss the pathway in the parasympathetic case. So in the case of the sympathetic nervous system, our pre ganglionic neuron always begins in our spinal cord. But in this case, it can begin in a spinal cord or it also can begin in the brain. | Autonomic Nervous System .txt |
Now, in the same exact way that we discussed our pathway of the electrical signal, let's discuss the pathway in the parasympathetic case. So in the case of the sympathetic nervous system, our pre ganglionic neuron always begins in our spinal cord. But in this case, it can begin in a spinal cord or it also can begin in the brain. So the cell body begins in our brain or spinal cord. And now the axon is relatively long. So the axon is long compared to the axon of the post ganglionic cell. | Autonomic Nervous System .txt |
So the cell body begins in our brain or spinal cord. And now the axon is relatively long. So the axon is long compared to the axon of the post ganglionic cell. So we still have our pre ganglionic cell that synapses with the post ganglionic cell. And in this case our neurotransmitter is also acetylcholine. Now we have a short post ganglionic axon. | Autonomic Nervous System .txt |
So we still have our pre ganglionic cell that synapses with the post ganglionic cell. And in this case our neurotransmitter is also acetylcholine. Now we have a short post ganglionic axon. In this case we had a long one. And now our synapse between the post ganglionic neuron and the fact the organ uses acetylcholine as a neurotransmitter, in this case we use epinephrine or norepinephrine. So this is a second difference between our sympathetic and parasympathetic nervous system. | Autonomic Nervous System .txt |
In this case we had a long one. And now our synapse between the post ganglionic neuron and the fact the organ uses acetylcholine as a neurotransmitter, in this case we use epinephrine or norepinephrine. So this is a second difference between our sympathetic and parasympathetic nervous system. So the pre ganglionic neuron begins either in a spinal cord or in the brain. It then carries our electrical signal via a long axon to our synapse that uses acetylcholine. And then the signal is passed down to this one and at this location it uses our acetylcholine once again. | Autonomic Nervous System .txt |
So the pre ganglionic neuron begins either in a spinal cord or in the brain. It then carries our electrical signal via a long axon to our synapse that uses acetylcholine. And then the signal is passed down to this one and at this location it uses our acetylcholine once again. So the major difference between our sympathetic and the parasympathetic is in the parasympathetic, both synapses use acetylcholine. In this case, only the pre uses our acetylcholine. The post uses epinephrine. | Autonomic Nervous System .txt |
So the major difference between our sympathetic and the parasympathetic is in the parasympathetic, both synapses use acetylcholine. In this case, only the pre uses our acetylcholine. The post uses epinephrine. In this case we have a long pre ganglionic and a short post ganglionic. Here we have a short pre ganglionic and a long pre ganglionic. In the sympathetic case it always begins in a spinal cord while in this case it begins either in the brain or in our spinal cord. | Autonomic Nervous System .txt |
In this case we have a long pre ganglionic and a short post ganglionic. Here we have a short pre ganglionic and a long pre ganglionic. In the sympathetic case it always begins in a spinal cord while in this case it begins either in the brain or in our spinal cord. Now, in the parasympathetic case we always have a pre ganglionic and opposed ganglionic neuron. In the case of the sympathetic we usually have a pre and opposed ganglionic. But in the case of the signal being transferred into our adrenal medulla we only have a single neuron. | Autonomic Nervous System .txt |
Now, in the parasympathetic case we always have a pre ganglionic and opposed ganglionic neuron. In the case of the sympathetic we usually have a pre and opposed ganglionic. But in the case of the signal being transferred into our adrenal medulla we only have a single neuron. In the pathway we have the pre ganglionic neuron. And once again, our sympathetic nervous system is responsible for monitoring and regulating the activities related with the fight or flight responses. But in the parasympathetic case we basically regulate the rest and digest activities. | Autonomic Nervous System .txt |
Well, for the most part, the amino acid can be used in biosynthetic processes to form new molecules. For example, we can use amino acids to build proteins. We can use amino acids to build nucleotide bases. But let's suppose we have all the proteins that we want, and we have all the nucleotide bases that our cells can actually use. What happens to any extra leftover amino acids? Well, you might be thinking we can store those amino acids for later use. | Deamination of Amino Acids .txt |
But let's suppose we have all the proteins that we want, and we have all the nucleotide bases that our cells can actually use. What happens to any extra leftover amino acids? Well, you might be thinking we can store those amino acids for later use. So in the same way that we can store glucose as glycogen, and we can store extra fatty acids as triglycerides, can we store extra amino acids inside our cells? And the answer is simply no. Our cells do not have a way to actually store any excess amino acids. | Deamination of Amino Acids .txt |
So in the same way that we can store glucose as glycogen, and we can store extra fatty acids as triglycerides, can we store extra amino acids inside our cells? And the answer is simply no. Our cells do not have a way to actually store any excess amino acids. And so what must happen to these extra amino acids is they must be broken down. Now, the majority of the breakdown of amino acids occurs inside our liver. But other cells, such as muscle cells, can also break down amino acids. | Deamination of Amino Acids .txt |
And so what must happen to these extra amino acids is they must be broken down. Now, the majority of the breakdown of amino acids occurs inside our liver. But other cells, such as muscle cells, can also break down amino acids. For example, inside our muscle cell, we basically break down branch chain amino acids such as leucine, isoleucine, and valine. So let's take a look at how we actually break down amino acids. Now, we have different ways by which we break down different amino acids, but let's begin by focusing on this two step process here. | Deamination of Amino Acids .txt |
For example, inside our muscle cell, we basically break down branch chain amino acids such as leucine, isoleucine, and valine. So let's take a look at how we actually break down amino acids. Now, we have different ways by which we break down different amino acids, but let's begin by focusing on this two step process here. So essentially, the goal in the breakdown of amino acids is first we have to remove that amino group from that amino acid to form our ammonia. The ammonium ultimately is fed into the urea cycle, and that removes that ammonium from the body and the leftover carbon skeleton that we have left over. After this process occurs, that is used to form energy molecules, and we'll talk about that in electra to come. | Deamination of Amino Acids .txt |
So essentially, the goal in the breakdown of amino acids is first we have to remove that amino group from that amino acid to form our ammonia. The ammonium ultimately is fed into the urea cycle, and that removes that ammonium from the body and the leftover carbon skeleton that we have left over. After this process occurs, that is used to form energy molecules, and we'll talk about that in electra to come. So this is a two step process by which first we take the amino acid. We undergo a transamination step in which we basically transfer this green group onto a different molecule. We form glutamate. | Deamination of Amino Acids .txt |
So this is a two step process by which first we take the amino acid. We undergo a transamination step in which we basically transfer this green group onto a different molecule. We form glutamate. And the second step, we actually have that diamondation step. So we deaminate, we remove the alpha amino group, and we form the ammonium, at which point this ammonium can now be fed into the urea cycle. Now, let's begin by focusing on just this reaction here. | Deamination of Amino Acids .txt |
And the second step, we actually have that diamondation step. So we deaminate, we remove the alpha amino group, and we form the ammonium, at which point this ammonium can now be fed into the urea cycle. Now, let's begin by focusing on just this reaction here. So we have transamination. transamination is catalyzed by an enzyme known as aminotransferase, and we also call it transaminase. But in this lecture, we're going to refer to it as simply aminotransferase. | Deamination of Amino Acids .txt |
So we have transamination. transamination is catalyzed by an enzyme known as aminotransferase, and we also call it transaminase. But in this lecture, we're going to refer to it as simply aminotransferase. Now, Aminotransferase, as we'll talk about in more detail in the next lecture, uses an important coenzyme, a vitamin B six derivative known as peridoxylphostate. So a periodoxyl phosphate needs to be present for this enzyme to actually be effective. If we have deficiency in this coenzyme here, this enzyme will not function correctly. | Deamination of Amino Acids .txt |
Now, Aminotransferase, as we'll talk about in more detail in the next lecture, uses an important coenzyme, a vitamin B six derivative known as peridoxylphostate. So a periodoxyl phosphate needs to be present for this enzyme to actually be effective. If we have deficiency in this coenzyme here, this enzyme will not function correctly. So this is a general process that takes place. We begin with some target amino acid that we have too much of. So we want to break this down. | Deamination of Amino Acids .txt |
So this is a general process that takes place. We begin with some target amino acid that we have too much of. So we want to break this down. We reacted with an alpha ketoacid, and we basically form these two products here. So we transfer this green group, the alpha amino group, onto this group here, remove this oxygen, and we form these two molecules. So we form another amino acid, which is actually a glutamate, as we have in this diagram here, and we form this alpha keto acid. | Deamination of Amino Acids .txt |
We reacted with an alpha ketoacid, and we basically form these two products here. So we transfer this green group, the alpha amino group, onto this group here, remove this oxygen, and we form these two molecules. So we form another amino acid, which is actually a glutamate, as we have in this diagram here, and we form this alpha keto acid. Now, this molecule can basically be used for energy purposes, as we'll see in a future lecture. But this molecule must further undergo a process, the diamondation step, to basically generate that free ammonium. So let's look at two examples of these processes. | Deamination of Amino Acids .txt |
Now, this molecule can basically be used for energy purposes, as we'll see in a future lecture. But this molecule must further undergo a process, the diamondation step, to basically generate that free ammonium. So let's look at two examples of these processes. So we have different aminotransferases, and two common examples are alanine and aspartate aminotransferases. So, as you might imagine, in this particular case, the beginning amino acid is alanine. In this case, it's aspartate. | Deamination of Amino Acids .txt |
So we have different aminotransferases, and two common examples are alanine and aspartate aminotransferases. So, as you might imagine, in this particular case, the beginning amino acid is alanine. In this case, it's aspartate. So in both cases, the alpha keto acid is alpha ketoglutrate. So we use this molecule to basically transfer this green alpha amino group onto the alpha ketoglutrate. Now, when we remove the alpha amino group, this green group from alanine, we basically form pyruvate. | Deamination of Amino Acids .txt |
So in both cases, the alpha keto acid is alpha ketoglutrate. So we use this molecule to basically transfer this green alpha amino group onto the alpha ketoglutrate. Now, when we remove the alpha amino group, this green group from alanine, we basically form pyruvate. When we do the same thing for aspartate, we form oxalo acetate. But because these two molecules are exactly the same, when we transfer that green group onto alpha key to glutarate, we basically form the glutamate. And it's the glutamate that goes on to undergo the oxidative diamondation step to basically abstract that ammonium, as we'll see in just a moment. | Deamination of Amino Acids .txt |
When we do the same thing for aspartate, we form oxalo acetate. But because these two molecules are exactly the same, when we transfer that green group onto alpha key to glutarate, we basically form the glutamate. And it's the glutamate that goes on to undergo the oxidative diamondation step to basically abstract that ammonium, as we'll see in just a moment. Now, the last thing I'd like to mention about this process is it goes both ways. So we can go this way, but we also go in reverse. So this reaction actually exists in equilibrium. | Deamination of Amino Acids .txt |
Now, the last thing I'd like to mention about this process is it goes both ways. So we can go this way, but we also go in reverse. So this reaction actually exists in equilibrium. And why is that important? Well, it's important the following way. So going this way, our cells can break down allenine and aspartate and other amino acids. | Deamination of Amino Acids .txt |
And why is that important? Well, it's important the following way. So going this way, our cells can break down allenine and aspartate and other amino acids. But going in reverse, that actually gives us a way to form new amino acids. So we can begin with these molecules and go on to form alanine, or aspartate if our cell actually needs to do that. Now, let's go on to step number two. | Deamination of Amino Acids .txt |
But going in reverse, that actually gives us a way to form new amino acids. So we can begin with these molecules and go on to form alanine, or aspartate if our cell actually needs to do that. Now, let's go on to step number two. So the oxidative diamondation step. So once we transfer that amino group from the target amino acid onto the alpha key to glutary to form the glutamate, what is the fate of that glutamate? Well, what we want to do is we want to deaminate the glutamate. | Deamination of Amino Acids .txt |
So the oxidative diamondation step. So once we transfer that amino group from the target amino acid onto the alpha key to glutary to form the glutamate, what is the fate of that glutamate? Well, what we want to do is we want to deaminate the glutamate. And this happens in a two step process. So we have a dehydrogenation, and then we have this hydrolysis reaction. So we take the glutamate, and we basically want to remove this h here and this h here. | Deamination of Amino Acids .txt |
And this happens in a two step process. So we have a dehydrogenation, and then we have this hydrolysis reaction. So we take the glutamate, and we basically want to remove this h here and this h here. We also want to remove two electrons. And so we form a pi bond between this carbon and this nitrogen. And so this is actually an oxidation reaction reaction, oxidation reduction reaction. | Deamination of Amino Acids .txt |
We also want to remove two electrons. And so we form a pi bond between this carbon and this nitrogen. And so this is actually an oxidation reaction reaction, oxidation reduction reaction. And so the molecule that we use as a coenzyme is NAD. Plus, now the enzyme that catalyze this step is no longer this enzyme. It's a different enzyme known as glutamate dehydrogenase. | Deamination of Amino Acids .txt |
And so the molecule that we use as a coenzyme is NAD. Plus, now the enzyme that catalyze this step is no longer this enzyme. It's a different enzyme known as glutamate dehydrogenase. Now, glutamate dehydrogenase is interesting because it not only uses NAD plus, but it can also use instead of the NAD plus, NADP plus. So we can replace this with NADP plus, but ultimately we use this or the enzyme uses this to basically remove the two electrons and the h to form the NADH. We also remove the h plus and we form a double bond between carbon and the nitrogen, and we form this shift based intermediate shown here. | Deamination of Amino Acids .txt |
Now, glutamate dehydrogenase is interesting because it not only uses NAD plus, but it can also use instead of the NAD plus, NADP plus. So we can replace this with NADP plus, but ultimately we use this or the enzyme uses this to basically remove the two electrons and the h to form the NADH. We also remove the h plus and we form a double bond between carbon and the nitrogen, and we form this shift based intermediate shown here. Now, in the second step, we actually have the diamondation step, or we can also see it as a hydrolysis step because we use a water to basically hydrolyze and remove that Ammonium. And so we replace the nitrogen, h two with an oxygen and we abstract that Ammonium. So we take the two HS from here and the two HS from the water, and we form that Ammonium. | Deamination of Amino Acids .txt |
Now, in the second step, we actually have the diamondation step, or we can also see it as a hydrolysis step because we use a water to basically hydrolyze and remove that Ammonium. And so we replace the nitrogen, h two with an oxygen and we abstract that Ammonium. So we take the two HS from here and the two HS from the water, and we form that Ammonium. And we also form the alpha ketoglutrate as the final product. Now, one interesting thing about glutamate dehydrogenase is that it is found in the mitochondria. Now, why is that important? | Deamination of Amino Acids .txt |
And we also form the alpha ketoglutrate as the final product. Now, one interesting thing about glutamate dehydrogenase is that it is found in the mitochondria. Now, why is that important? Well, the final product form of this process is Ammonium. And Ammonium is a very toxic substance. And so if Ammonium was readily formed in the styroplasm, that can actually damage the cell. | Deamination of Amino Acids .txt |
Well, the final product form of this process is Ammonium. And Ammonium is a very toxic substance. And so if Ammonium was readily formed in the styroplasm, that can actually damage the cell. And so to prevent that from actually happening, our cell sequesters the glutamate dehydrogenase in the mitochondria and it basically keeps that Ammonium inside the mitochondria, preventing it from actually damaging the cell. Another important thing about this reaction is the same thing we mentioned here. These arrows go both ways. | Deamination of Amino Acids .txt |
And so to prevent that from actually happening, our cell sequesters the glutamate dehydrogenase in the mitochondria and it basically keeps that Ammonium inside the mitochondria, preventing it from actually damaging the cell. Another important thing about this reaction is the same thing we mentioned here. These arrows go both ways. And so we can basically go this way, but if the conditions change, we can also go this way. Now, under normal conditions, the reaction actually goes forward. Why? | Deamination of Amino Acids .txt |
And so we can basically go this way, but if the conditions change, we can also go this way. Now, under normal conditions, the reaction actually goes forward. Why? Well, because normally, every time we for the Ammonium product, that Ammonium is used up in the urea cycle. And so if we continually use up this final product, that will drive this reaction forward. So if we summarize these two reactions, the transamination and the oxidative deamination, we basically form this diagram here. | Deamination of Amino Acids .txt |
Well, because normally, every time we for the Ammonium product, that Ammonium is used up in the urea cycle. And so if we continually use up this final product, that will drive this reaction forward. So if we summarize these two reactions, the transamination and the oxidative deamination, we basically form this diagram here. So we begin with the target amino acid, and we have the alpha key to glutrate. As we saw in this particular case, this is catalyzed by aminotransferase. And so we ultimately form a glutamate and the alpha key to acid, in this case, pyruvate, in this case, oxalo acetate. | Deamination of Amino Acids .txt |
So we begin with the target amino acid, and we have the alpha key to glutrate. As we saw in this particular case, this is catalyzed by aminotransferase. And so we ultimately form a glutamate and the alpha key to acid, in this case, pyruvate, in this case, oxalo acetate. Now, in the second step, that is catalyzed by glutamate dehydrogenase, the glutamate reacts with the NAD plus or NADP plus and water to basically form the alpha key to gluterate and that Ammonium. And so this Ammonium then goes into the urea cycle. It is used up, and so this reaction is driven in this direction. | Deamination of Amino Acids .txt |
Now, in the second step, that is catalyzed by glutamate dehydrogenase, the glutamate reacts with the NAD plus or NADP plus and water to basically form the alpha key to gluterate and that Ammonium. And so this Ammonium then goes into the urea cycle. It is used up, and so this reaction is driven in this direction. So we see that the majority of amino acids inside our cells, more specifically our liver cells, hepatics basically undergo this two step process to deaminate that amino acid. Now, other amino acids such as Serene and three anine undergo other processes, processes to basically deaminate it. So in this case, we have a two step process that deaminates the amino acid. | Deamination of Amino Acids .txt |
So we see that the majority of amino acids inside our cells, more specifically our liver cells, hepatics basically undergo this two step process to deaminate that amino acid. Now, other amino acids such as Serene and three anine undergo other processes, processes to basically deaminate it. So in this case, we have a two step process that deaminates the amino acid. But for Serene and three anine, this is a single step process and it's catalyzed by single enzyme, a dehydrates. So we call it a dehydrates because there is a dehydration reaction that precedes a deamination reaction, as we'll see in just a moment. So for serine, we have serine dehydrates that basically deaminates the serine into Pyruvate and that forms Ammonium. | Deamination of Amino Acids .txt |
But for Serene and three anine, this is a single step process and it's catalyzed by single enzyme, a dehydrates. So we call it a dehydrates because there is a dehydration reaction that precedes a deamination reaction, as we'll see in just a moment. So for serine, we have serine dehydrates that basically deaminates the serine into Pyruvate and that forms Ammonium. For three enine, we form alpha, ketobutyrate, and the ammonium, the Ammonium goes into the urea cycle. These can be used for energy purposes. Now, to see exactly what happens, let's focus on this reaction here. | Deamination of Amino Acids .txt |
For three enine, we form alpha, ketobutyrate, and the ammonium, the Ammonium goes into the urea cycle. These can be used for energy purposes. Now, to see exactly what happens, let's focus on this reaction here. Reaction one. So we begin with our serine. And this enzyme dehydrates basically allows us to undergo a dehydration step. | Deamination of Amino Acids .txt |
Reaction one. So we begin with our serine. And this enzyme dehydrates basically allows us to undergo a dehydration step. And so what happens is this hydroxide group combines with an H atom, this H atom here, to basically form a double bond between this carbon, this carbon, and we form this high energy intermediate molecule. Now, this high energy intermediate molecule is unstable, and so it rarely converts into this final product. And this is our diamondation step. | Deamination of Amino Acids .txt |
And so what happens is this hydroxide group combines with an H atom, this H atom here, to basically form a double bond between this carbon, this carbon, and we form this high energy intermediate molecule. Now, this high energy intermediate molecule is unstable, and so it rarely converts into this final product. And this is our diamondation step. So this diamondation step is similar to this one here because we also use water in this hydrolysis step. So we essentially allow this group here to be kicked off. We form that Ammonium, and that Ammonium then goes into the urea cycle. | Deamination of Amino Acids .txt |
So this diamondation step is similar to this one here because we also use water in this hydrolysis step. So we essentially allow this group here to be kicked off. We form that Ammonium, and that Ammonium then goes into the urea cycle. So this is basically the process by which we deaminate amino acids. And by deaminating the amino acids, we basically form carbon skeletons and we form Ammonium. The Ammonium can be used in the urea cycle, and that carbon skeleton can be used to basically form energy molecules, as we'll see in a future lecture. | Deamination of Amino Acids .txt |
It's simply a combination of two different types of protein purification techniques. So in twodimensional gel electrophoresis, we take our mixture of proteins and we first expose it to isoelectrofocusing. We separate the proteins based on their isoelectric point. So the PH value at which that particular protein basically has a net charge of zero. And after that, we expose that solution, that mixture of proteins, to the process of SDS polyacrylamide gel electrophoresis, also known as SDS Page. So P is the first letter. | Two Dimensional Gel Electrophoresis.txt |
So the PH value at which that particular protein basically has a net charge of zero. And after that, we expose that solution, that mixture of proteins, to the process of SDS polyacrylamide gel electrophoresis, also known as SDS Page. So P is the first letter. Then we have the A. Then we have the g then we have the E. So SD eight SDS page So isoelectric focusing can be combined with SDS polyacrylamide geelectrophrases, or SDS Page to create a more effective and more efficient way of purifying our crude mixture of proteins. And to see exactly what we mean, let's take a look at the following two steps. | Two Dimensional Gel Electrophoresis.txt |
Then we have the A. Then we have the g then we have the E. So SD eight SDS page So isoelectric focusing can be combined with SDS polyacrylamide geelectrophrases, or SDS Page to create a more effective and more efficient way of purifying our crude mixture of proteins. And to see exactly what we mean, let's take a look at the following two steps. Now, we're not going to focus too much on each one of these steps because we spoke about these in detail in previous lectures. We're simply going to show you the fact that we can combine these two techniques to basically create a more effective method. So, in the first step, we take our crude mixture of proteins found in the following beaker, and we expose it to isoelectric focusing. | Two Dimensional Gel Electrophoresis.txt |
Now, we're not going to focus too much on each one of these steps because we spoke about these in detail in previous lectures. We're simply going to show you the fact that we can combine these two techniques to basically create a more effective method. So, in the first step, we take our crude mixture of proteins found in the following beaker, and we expose it to isoelectric focusing. So remember, in isoelectric focusing, we essentially have this gel. And that gel contains a PH gradient. So on one side, we have a low PH acidic, and that's when we have many of these positively charged H ions. | Two Dimensional Gel Electrophoresis.txt |
So remember, in isoelectric focusing, we essentially have this gel. And that gel contains a PH gradient. So on one side, we have a low PH acidic, and that's when we have many of these positively charged H ions. And so we have a positive charge on this end. On the other side, we have a low concentration of H plus ions. We have a high PH, a basic environment. | Two Dimensional Gel Electrophoresis.txt |
And so we have a positive charge on this end. On the other side, we have a low concentration of H plus ions. We have a high PH, a basic environment. We have a negative charge. And so when we take this mixture of proteins and dump them onto the gel, they will begin to separate on the basis of their net charge. And so they will essentially continue moving as a result of that electric field. | Two Dimensional Gel Electrophoresis.txt |
We have a negative charge. And so when we take this mixture of proteins and dump them onto the gel, they will begin to separate on the basis of their net charge. And so they will essentially continue moving as a result of that electric field. And they will stop moving when their net charge is zero. And that is what we call the isoelectric point. So a mixture of proteins is first exposed to isoelectric focusing. | Two Dimensional Gel Electrophoresis.txt |
And they will stop moving when their net charge is zero. And that is what we call the isoelectric point. So a mixture of proteins is first exposed to isoelectric focusing. This separates the proteins based on their isoelectric point. So the PH value at which the net charge on the protein is zero. So if two or more proteins, however, have the same pi value, they will be found on the same exact band in this diagram. | Two Dimensional Gel Electrophoresis.txt |
This separates the proteins based on their isoelectric point. So the PH value at which the net charge on the protein is zero. So if two or more proteins, however, have the same pi value, they will be found on the same exact band in this diagram. So we have 12345 of these different bands. And what each of these bands basically means, we have either a single or many proteins within each one of these bands. For example, let's suppose we're looking at this band. | Two Dimensional Gel Electrophoresis.txt |
So we have 12345 of these different bands. And what each of these bands basically means, we have either a single or many proteins within each one of these bands. For example, let's suppose we're looking at this band. Here what this band basically means. A single protein or many proteins exist along the following region. And all these proteins basically have the same exact isoelectric point, the same exact pi value. | Two Dimensional Gel Electrophoresis.txt |
Here what this band basically means. A single protein or many proteins exist along the following region. And all these proteins basically have the same exact isoelectric point, the same exact pi value. And the same thing is true for these other bands, as shown. Now, if we take this horizontal slap and we place it into our SDS Page setup, we can now separate our proteins based on size. So this is one direction, the horizontal direction of separation, and this is our vertical direction of separation. | Two Dimensional Gel Electrophoresis.txt |
And the same thing is true for these other bands, as shown. Now, if we take this horizontal slap and we place it into our SDS Page setup, we can now separate our proteins based on size. So this is one direction, the horizontal direction of separation, and this is our vertical direction of separation. And that's why this is called a two dimensional gel electrophoresis process, because we separate along the x axis, then along the y axis, and those are two different dimensions. So once we take this and place it into our electrophoresis setup, we see that what begins to happen is they begin to migrate down towards the positively charged end of this SDS Page setup. And so if any one of these bands consists of different proteins that have different mass values, that are different sizes, we're going to be able to separate them along the vertical direction based on their size. | Two Dimensional Gel Electrophoresis.txt |
And that's why this is called a two dimensional gel electrophoresis process, because we separate along the x axis, then along the y axis, and those are two different dimensions. So once we take this and place it into our electrophoresis setup, we see that what begins to happen is they begin to migrate down towards the positively charged end of this SDS Page setup. And so if any one of these bands consists of different proteins that have different mass values, that are different sizes, we're going to be able to separate them along the vertical direction based on their size. So in this case, we separate them based on their isoelectric point, but in this case, we separate them based on their mass, based on their size. So we see that this slab, this band, consists of at least four different proteins, because these four different proteins contain different size values, different masses. Likewise, the second band consists of at least two proteins, the third band consists of at least one, two, three proteins. | Two Dimensional Gel Electrophoresis.txt |
So in this case, we separate them based on their isoelectric point, but in this case, we separate them based on their mass, based on their size. So we see that this slab, this band, consists of at least four different proteins, because these four different proteins contain different size values, different masses. Likewise, the second band consists of at least two proteins, the third band consists of at least one, two, three proteins. The fourth band consists of at least three proteins, and the fifth band consists of at least five different proteins. Now, it's not to say that we don't have more proteins here. For example, the reason to say we have at least five proteins in this section is because two proteins that have the same exact isoelectric point can also have the same exact mass. | Two Dimensional Gel Electrophoresis.txt |
The fourth band consists of at least three proteins, and the fifth band consists of at least five different proteins. Now, it's not to say that we don't have more proteins here. For example, the reason to say we have at least five proteins in this section is because two proteins that have the same exact isoelectric point can also have the same exact mass. And so each one of these sections, each one of these individual bands can consist of two or more proteins, but it also can consist of only a single protein. To basically determine if we have more proteins in each one of these sections, we have to carry out some other type of purification process that separates the proteins based on some other type of property. So in the second method, the horizontal gel lane that contains the protein, so this entire gel lane is placed onto the SDS Page apparatus. | Two Dimensional Gel Electrophoresis.txt |
And so each one of these sections, each one of these individual bands can consist of two or more proteins, but it also can consist of only a single protein. To basically determine if we have more proteins in each one of these sections, we have to carry out some other type of purification process that separates the proteins based on some other type of property. So in the second method, the horizontal gel lane that contains the protein, so this entire gel lane is placed onto the SDS Page apparatus. So SDS polyacrylamide gel electrophoresis apparatus, the proteins now begin to move as a result of that electric field in the perpendicular direction with respect to the direction in this case. So here we have along the x axis, and here we have movement along the y axis. So the x axis is perpendicular to the y axis, so they begin to move downward. | Two Dimensional Gel Electrophoresis.txt |
So SDS polyacrylamide gel electrophoresis apparatus, the proteins now begin to move as a result of that electric field in the perpendicular direction with respect to the direction in this case. So here we have along the x axis, and here we have movement along the y axis. So the x axis is perpendicular to the y axis, so they begin to move downward. This will separate the proteins that have identical pi values based on their different masses, different sizes. So we conclude that the two dimensional gel electrofreezes process is a highly effective method that separates the mixtures of the mixture proteins based on two different properties, so their isoelectric point and their size. So the horizontal direction is the isoelectric point. | Two Dimensional Gel Electrophoresis.txt |
This will separate the proteins that have identical pi values based on their different masses, different sizes. So we conclude that the two dimensional gel electrofreezes process is a highly effective method that separates the mixtures of the mixture proteins based on two different properties, so their isoelectric point and their size. So the horizontal direction is the isoelectric point. It separates the proteins based on the PH at which they have a net charge of zero, and the second vertical dimension basically separates them based on size. So this is the process of two dimensional gel electrophoresis. It combines isoelectric focusing and st polyacrylamide gel electrophree. | Two Dimensional Gel Electrophoresis.txt |
And it generates the action potentials on the cell membrane, and it moves the electrical signal along the axon and passes that electric signal down to adjacent cells. And by this method, our cells can communicate with one another in a direct and rapid fashion over very short distances. Now, before we actually describe how the neuron generates the action potential and what the action potential is, let's describe the cell membrane of the neuron. When the neuron is at rest, that is, when it is not generating any action potential. So this is known as the resting membrane of our neuron. Now, the resting membrane contains a certain voltage difference. | Resting Membrane Potential of Neuron.txt |
When the neuron is at rest, that is, when it is not generating any action potential. So this is known as the resting membrane of our neuron. Now, the resting membrane contains a certain voltage difference. There is a certain voltage difference between the inside and the outside of the cell, and this is known as the resting membrane potential. So, once again, the resting membrane potential is the voltage difference or the electric potential difference between the inside and the outside of a neuron that is not generating any action potential. So let's begin by looking at the following diagram. | Resting Membrane Potential of Neuron.txt |
There is a certain voltage difference between the inside and the outside of the cell, and this is known as the resting membrane potential. So, once again, the resting membrane potential is the voltage difference or the electric potential difference between the inside and the outside of a neuron that is not generating any action potential. So let's begin by looking at the following diagram. So this diagram describes the relative concentrations of sodium ions and potassium ions on the outside and inside of the neuron cell membrane. So this is the phospholipid bilayer, the membrane of the neuron, let's say, found on the exxon hillock where the action potential is generated. But, of course, no action potential is being generated in this particular case. | Resting Membrane Potential of Neuron.txt |
So this diagram describes the relative concentrations of sodium ions and potassium ions on the outside and inside of the neuron cell membrane. So this is the phospholipid bilayer, the membrane of the neuron, let's say, found on the exxon hillock where the action potential is generated. But, of course, no action potential is being generated in this particular case. So this is the outside portion of the cell. It's the extracellular portion of the membrane. This is the inside portion of the cell, the cytoplasmic side of our membrane. | Resting Membrane Potential of Neuron.txt |
So this is the outside portion of the cell. It's the extracellular portion of the membrane. This is the inside portion of the cell, the cytoplasmic side of our membrane. Now, these red dots describe sodium ions, and these purple dots describe our potassium ions. And each one of these ions are cat ions. That means they each have a positive charge of one. | Resting Membrane Potential of Neuron.txt |
Now, these red dots describe sodium ions, and these purple dots describe our potassium ions. And each one of these ions are cat ions. That means they each have a positive charge of one. Now, notice we have many more of these red dots on the outside than on the inside, and many more of these purple dots on the inside than on the outside. So that implies that when the membrane is resting, when it is not generating any action potential, we have many more sodium ions on the outside than on the inside. And conversely, we have many more potassium on the inside than on the outside. | Resting Membrane Potential of Neuron.txt |
Now, notice we have many more of these red dots on the outside than on the inside, and many more of these purple dots on the inside than on the outside. So that implies that when the membrane is resting, when it is not generating any action potential, we have many more sodium ions on the outside than on the inside. And conversely, we have many more potassium on the inside than on the outside. And this table describes what the concentrations are. So for sodium on the inside, we have 15 millimolar. And for the outside, we have 150 millimolar. | Resting Membrane Potential of Neuron.txt |
And this table describes what the concentrations are. So for sodium on the inside, we have 15 millimolar. And for the outside, we have 150 millimolar. So the ratio is ten to one. So for every one sodium we find on the inside, we have ten sodium ions on the outside. Now, for potassium, it's the opposite. | Resting Membrane Potential of Neuron.txt |
So the ratio is ten to one. So for every one sodium we find on the inside, we have ten sodium ions on the outside. Now, for potassium, it's the opposite. We have more. On the inside, we have 130 millimolar, and only five millimolar on the outside. So the ratio is 26 to one. | Resting Membrane Potential of Neuron.txt |
We have more. On the inside, we have 130 millimolar, and only five millimolar on the outside. So the ratio is 26 to one. For every one potassium we find on the outside, we have 26 potassiums on the inside of the resting membrane of our neuron. Now, this picture doesn't actually describe everything correctly because we also have other ions that bear a negative charge. So we also have chloride ions, we have bicarbonate, and we have proteins that all have negative charge and they're found on the inside as well as on the outside of the cell. | Resting Membrane Potential of Neuron.txt |
For every one potassium we find on the outside, we have 26 potassiums on the inside of the resting membrane of our neuron. Now, this picture doesn't actually describe everything correctly because we also have other ions that bear a negative charge. So we also have chloride ions, we have bicarbonate, and we have proteins that all have negative charge and they're found on the inside as well as on the outside of the cell. Now, we're going to begin by assuming something called electroneutrality. So electroneutrality means that all the negative charges cancel out all the positive charges on the inside, and likewise all the negative charges of all the negatively charged ions cancel out all the positive charges of all the positively charged ions. So this is known as electron neutrality. | Resting Membrane Potential of Neuron.txt |
Now, we're going to begin by assuming something called electroneutrality. So electroneutrality means that all the negative charges cancel out all the positive charges on the inside, and likewise all the negative charges of all the negatively charged ions cancel out all the positive charges of all the positively charged ions. So this is known as electron neutrality. So the outside and the inside are neutral with respect to the charge. So we're going to begin by assuming that. Now the question is let's take a look at the following concentration amount. | Resting Membrane Potential of Neuron.txt |
So the outside and the inside are neutral with respect to the charge. So we're going to begin by assuming that. Now the question is let's take a look at the following concentration amount. So we have many more of these sodiums on the outside than on the inside. And that means if the sodium ions can somehow flow across the membrane, they would travel from the high concentration the outside to the low concentration the inside. And likewise, if these potassium ions could somehow travel across the membrane, they would travel from the high concentration the inside to the low concentration the outside. | Resting Membrane Potential of Neuron.txt |
So we have many more of these sodiums on the outside than on the inside. And that means if the sodium ions can somehow flow across the membrane, they would travel from the high concentration the outside to the low concentration the inside. And likewise, if these potassium ions could somehow travel across the membrane, they would travel from the high concentration the inside to the low concentration the outside. Now, of course, because these ions contain positive charges, we know that they cannot actually diffuse across the membrane. Now, what the membrane actually contains is special proteins that facilitate the diffusion passively of these ions. And we have many more of these potassium membrane proteins than the sodium membrane proteins. | Resting Membrane Potential of Neuron.txt |
Now, of course, because these ions contain positive charges, we know that they cannot actually diffuse across the membrane. Now, what the membrane actually contains is special proteins that facilitate the diffusion passively of these ions. And we have many more of these potassium membrane proteins than the sodium membrane proteins. And that implies that our membrane is much more permeable to potassium than it is to sodium. And that implies that our potassium will travel across the membrane much more at a much higher rate than our sodium will. So once again, the membrane of the neuron is naturally much more permeable to potassium than to the sodium. | Resting Membrane Potential of Neuron.txt |
And that implies that our membrane is much more permeable to potassium than it is to sodium. And that implies that our potassium will travel across the membrane much more at a much higher rate than our sodium will. So once again, the membrane of the neuron is naturally much more permeable to potassium than to the sodium. This means that the membrane contains more protein channels that facilitate our passive diffusion of potassium than of sodium. And therefore more potassium ions will leave the cell, then compared to our sodium ions will enter our cell. So this is described in the following diagram. | Resting Membrane Potential of Neuron.txt |
This means that the membrane contains more protein channels that facilitate our passive diffusion of potassium than of sodium. And therefore more potassium ions will leave the cell, then compared to our sodium ions will enter our cell. So this is described in the following diagram. So we have these facilitated transfer proteins. We have the ones that transport our potassium from the inside to the outside, from a high to a low concentration. And we have these transfer proteins that transport our sodium from the high from the outside to the low to the inside. | Resting Membrane Potential of Neuron.txt |
So we have these facilitated transfer proteins. We have the ones that transport our potassium from the inside to the outside, from a high to a low concentration. And we have these transfer proteins that transport our sodium from the high from the outside to the low to the inside. And we also have proteins that actually actively transport our potassium and sodium. And we're going to discuss these in much more detail in the next several lectures. This is known as the ATPase protein. | Resting Membrane Potential of Neuron.txt |
And we also have proteins that actually actively transport our potassium and sodium. And we're going to discuss these in much more detail in the next several lectures. This is known as the ATPase protein. Now, the question that we want to basically ask next is the following. So, we begin by assuming that the charge on the outside and the inside is exactly the same. It's zero. | Resting Membrane Potential of Neuron.txt |
Now, the question that we want to basically ask next is the following. So, we begin by assuming that the charge on the outside and the inside is exactly the same. It's zero. So that means the voltage difference between the outside and inside is zero. But we know that the voltage is not zero. If we actually try to find what the voltage is using some type of instrument, we'll see that it's not zero. | Resting Membrane Potential of Neuron.txt |
So that means the voltage difference between the outside and inside is zero. But we know that the voltage is not zero. If we actually try to find what the voltage is using some type of instrument, we'll see that it's not zero. So the question is, what exactly is the voltage difference between the cell membrane of a resting membrane and how is it generated? So, let's begin. For the time being. | Resting Membrane Potential of Neuron.txt |
So the question is, what exactly is the voltage difference between the cell membrane of a resting membrane and how is it generated? So, let's begin. For the time being. Let's begin by assuming that the cell is only permeable to our potassium. So as potassium leaves the cell, it travels from the inside to the outside via these proteins that passively diffuse our molecules, our ions. So as our potassium leaves the cell, we have less positively charged ions. | Resting Membrane Potential of Neuron.txt |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.