Cholesterol Synthesis How Our Bodies Make Cholesterol. Hey everyone, in this I’m going to talk to you guys about cholesterol synthesis and metabolism. I’m going to talk to you guys about the purpose of cholesterol, why we actually need cholesterol in our body.
I’m also going to talk to you guys about important steps in the cholesterol synthesis pathway. What are some of the critical regulatory enzymes in the pathway, how some of our pharmaceutical drugs actually work to regulate cholesterol in our bodies. And also, I’m also going to talk to you guys about how cholesterol is stored within our body.
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So to begin, here is the chemical structure of cholesterol. Cholesterol is actually a lipid, which means it’s hydrophobic. It’s a required precursor for vitamin D production, steroid production. It’s required for membrane stability, and it’s required for the production of bile salts. Now, cholesterol structure of cholesterol is characterized by a few different things.
Cholesterol Synthesis How Our Bodies Make Cholesterol
One is that it has four nonaramatic rings. It has one carbon double bond, it has one side chain, and it also has one hydroxyl group. Now, approximately 65% of plasma cholesterol is stored as cholesterol Ester. And I’ll get into that a bit more later as to what cholesterol Ester is. And finally, most cholesterol is actually produced in the liver, the adrenal glands, the intestines, and also in the gonans.And most of this is because a lot of these organs are involved in steroid production.
Cholesterol Synthesis How Our Bodies Make Cholesterol The two beginning precursors in cholesterol synthesis are acidic away and acetyl acidlcoa. Now, they actually come together via the enzyme HMG COA synthase to produce three hydroxy, three methyl glute or HMG COA. Now, HMG COA can be used for a couple of different pathways.
One, if it’s in the mitochondria, it can actually be used to produce ketone bodies in the liver. Now, I’ll get into that in another video, but if it’s in the cytosol, it can actually undergo a process by the enzyme HMGCoA reductase and produce metal ONIC acid.
Cholesterol Synthesis How Our Bodies Make Cholesterol Now, HMG COA reductase is the critically important enzyme in cholesterol synthesis pathway. This enzyme requires two NADPH, and it is the rate limiting step, which means it’s heavily regulated. It’s actually regulated by glucagon and amp. Glucagon and amp actually inhibit this enzyme. Insulin actually activates HMG COA reductase, and it’s actually regulated by its expression or its synthesis.
Where does cholesterol synthesis occur in the cell
And its synthesis is actually inhibited by glucose and amp and actually operated by insulin as well. Now, its synthesis H and G. Coa reductase synthesis is actually induced by the transcription factor steroid response element binding protein, or SREBP. And finally, because this enzyme is a rate limiting step and it’s highly regulated, this is actually the target of the pharmaceutical drug group known as Statins. So you might have heard of Levostanins.
Cholesterol Synthesis How Our Bodies Make Cholesterol Statins are cholesterol regulating drugs. They actually help to reduce cholesterol levels in our bodies. And this is how it does it and actually inhibit HMG COA reductive. So that is something very important for you guys to remember. Once metalanic acid is produced, it will actually undergo or actually go through a pathway known as the Mevillonate pathway requires three ATP, and it produces something known as isopentinopyophosate.
Cholesterol Synthesis How Our Bodies Make Cholesterol Now, isopentinopyrophosate actually takes six of these isopentinopyoposates and produces Squalene. So you actually need six isopentinopyrophosates to produce squaline. Then Squaline is actually processed through a few reaction steps into Linostro, and then Linostro.
will actually be processed via many different reaction steps into cholesterol. So, as you can see, I have dashed arrows here, which means I’m skipping over a few steps in this pathway. But these are the important intermediates I want you guys to remember for this cholesterol synthesis pathway and an easy way to remember it.
4 stages of cholesterol biosynthesis
Cholesterol Synthesis How Our Bodies Make Cholesterol So I’ll just try to remember that, guys, metalonic acid, isopentinopyophosate, Squaline, Linostrol and cholesterol. Now, cholesterol also acts as a negative feedback regulator on its own production, and it does that by actually negatively regulating HMG COA reductase as well.
And it does that by actually inhibiting a protein known as SCAP, which is a steroid binding protein. Now, SCAP typically, if it’s not bound to cholesterol, if cholesterol is not around, if it’s not bound to cholesterol, SCAP can actually cleave and lead to the cleavage and activation of SREBP. However, when cholesterol is around, if it’s been produced, or if it’s in excess, it can actually lead to the binding of SCAP.
Cholesterol can actually bind to SCAP, so that means SCAP can not actually lead to the cleavage and activation of SREBP. So that’s how cholesterol actually negatively regulates its own production. Now, I just want to get into more of the chemistry about some of these intermediates. Now, as you can see, metal ONIC acid can actually be produced through.
the Melanate pathway into isopentinopyophosate. And as I mentioned before, it takes about six isopentino pyrophosphates to make squalene, and you can actually see the different parts of this isopentinopyophosate insqualene. So this section of isopentinopyophosate is actually used six times in scaling. So that’s how we know there are six isoftenhyl pyrophosphate used in squalane.
Cholesterol synthesis in liver
And then once Squaline is produced, this squaline backbone will actually go through circularization to produce the nonaromatic rings of cholesterol via a few different reaction steps into a nostril. Now, once we have Linostrual, you can see it’s getting pretty close to what cholesterol looks like. But Nevertheless, Linostral to cholesterol still takes 18 reaction steps to get to cholesterol production.
So I just wanted to show you guys just how the chemistry, how we go from simple monomers. And the monomers are actually used to form somewhat like a polymer, and that polymer goes through a circularization reaction to get cholesterol. And it takes many, many different reaction steps to produce cholesterol. So I don’t want you guys to think it’s a very simple pathway, it’s a very complex pathway.
And one final point I want you guys to know is that many of these steps, especially from swelling through lineostrial and through cholesterol production, these reaction steps require enzymes that are located on or near to the endoplasmic reticulum interface. So a lot of these reactions occur at the interface of the endoplasmic reticulum. Now once cholesterol has been produced, how is it stored as cholesterol Ester? I talked about cholesterol Ester or otherwise known as cholesterol Ester. So how is cholesterol actually stored as cholesterol Ester?
Regulation of cholesterol synthesis
Well it actually undergoes a reaction through the enzyme Acad. If it’s in the cell, if it’s in a cell it undergoes a reaction by the enzyme ACAT or ACell COA cholesterol ACell transferase or ACAT and this occurs at the er. Now what it does is it actually takes the ACIL chain from ACIL COA and adds it to the hydroxyl group of the cholesterol to form a cholesterol Ester so that’s the storage form of cholesterol. Now if cholesterol is not in the cell.
if it’s in the extracellular environment It actually is operated or acted on by a different enzyme known as LCAT which is Lechethyn cholesterol acidis rays and this occurs in the serum and it actually uses phosphatidyl choline it uses an acid group from the phosphatidl choline to attach to the hydroxyl group of cholesterol to form cholesterol Ester. Now as I mentioned before Cholesterol Ester is very important to know because approximately 65% of plasma cholesterol is actually stored as this cholesterol Ester.
Now once you have cholesterol Ester stored how does it actually go back to cholesterol? Well it actually does that by an enzyme known as cholesterol S. Rays which is very easy to remember. So cholesterol estraze actually acts on cholesterol Ester, removes the acid group and forms cholesterol again in its active form. Anyways, guys, that was a quick look at the cholesterol synthesis pathway.
Cholesterol function
I hope you found this video helpful and anyways, guys, thank you so much for watching and have a great day. Hey, everyone, in this I’m going to talk to you guys about cholesterol synthesis and metabolism. So in this video, I’m going to talk to you guys about the purpose of cholesterol, why we actually need cholesterol in our body. I’m also going to talk to you guys about important steps in the cholesterol synthesis pathway. What are some of the critical regulatory enzymes in the pathway, how some of our pharmaceutical drugs actually work to regulate cholesterol in our bodies. And also, I’m also going to talk to you guys about how cholesterol is stored within our body.
So to begin, here is the chemical structure of cholesterol. Cholesterol is actually a lipid, which means it’s hydrophobic. It’s a required precursor for vitamin D production, steroid production. It’s required for membrane stability, and it’s required for the production of bile salts. Now, cholesterol structure of cholesterol is characterized by a few different things.
How is cholesterol removed from the body
One is that it has four nonaramatic rings. It has one carbon double bond, it has one side chain, and it also has one hydroxyl group. Now, approximately 65% of plasma cholesterol is stored as cholesterol Ester. And I’ll get into that a bit more later as to what cholesterol Ester is. And finally, most cholesterol is actually produced in the liver, the adrenal glands, the intestines, and also in the gonans.
And most of this is because a lot of these organs are involved in steroid production. The two beginning precursors in cholesterol synthesis are acidic away and acetyl acidlcoa. Now, they actually come together via the enzyme HMG COA synthase to produce three hydroxy, three methyl glute or HMG COA. Now, HMG COA can be used for a couple of different pathways.
One, if it’s in the mitochondria, it can actually be used to produce ketone bodies in the liver. Now, I’ll get into that in another video, but if it’s in the cytosol, it can actually undergo a process by the enzyme HMGCoA reductase and produce metal ONIC acid.
what reduces cholesterol quickly?
Now, HMG COA reductase is the critically important enzyme in cholesterol synthesis pathway. This enzyme requires two NADPH, and it is the rate limiting step, which means it’s heavily regulated. It’s actually regulated by glucagon and amp. Glucagon and amp actually inhibit this enzyme. Insulin actually activates HMG COA reductase, and it’s actually regulated by its expression or its synthesis.
And its synthesis is actually inhibited by glucose and amp and actually operated by insulin as well. Now, its synthesis H and G. Coa reductase synthesis is actually induced by the transcription factor steroid response element binding protein, or SREBP. And finally, because this enzyme is a rate limiting step and it’s highly regulated, this is actually the target of the pharmaceutical drug group known as Statins. So you might have heard of Levostanins.
what reduces cholesterol quickly food
Statins are cholesterol regulating drugs. They actually help to reduce cholesterol levels in our bodies. And this is how it does it and actually inhibit HMG COA reductive. So that is something very important for you guys to remember. Once metalanic acid is produced, it will actually undergo or actually go through a pathway known as the Mevillonate pathway requires three ATP, and it produces something known as isopentinopyophosate.
Now, isopentinopyrophosate actually takes six of these isopentinopyoposates and produces Squalene. So you actually need six isopentinopyrophosates to produce squaline. Then Squaline is actually processed through a few reaction steps into Linostro, and then Linostro will actually be processed via many different reaction steps into cholesterol.
So, as you can see, I have dashed arrows here, which means I’m skipping over a few steps in this pathway. But these are the important intermediates I want you guys to remember for this cholesterol synthesis pathway and an easy way to remember it.
what reduces cholesterol quickly
So I’ll just try to remember that, guys, metalonic acid, isopentinopyophosate, Squaline, Linostrol and cholesterol. Now, cholesterol also acts as a negative feedback regulator on its own production, and it does that by actually negatively regulating HMG COA reductase as well. And it does that by actually inhibiting a protein known as SCAP, which is a steroid binding protein.
Now, SCAP typically, if it’s not bound to cholesterol, if cholesterol is not around, if it’s not bound to cholesterol, SCAP can actually cleave and lead to the cleavage and activation of SREBP. However, when cholesterol is around, if it’s been produced, or if it’s in excess, it can actually lead to the binding of SCAP.
Cholesterol can actually bind to SCAP, so that means SCAP can not actually lead to the cleavage and activation of SREBP. So that’s how cholesterol actually negatively regulates its own production.
Now, I just want to get into more of the chemistry about some of these intermediates. Now, as you can see, metal ONIC acid can actually be produced through the Melanate pathway into isopentinopyophosate. And as I mentioned before, it takes about six isopentino pyrophosphates to make squalene, and you can actually see the different parts of this isopentinopyophosate insqualene. So this section of isopentinopyophosate is actually used six times in scaling. So that’s how we know there are six isoftenhyl pyrophosphate used in squalane.
What is the best drink to lower cholesterol
And then once Squaline is produced, this squaline backbone will actually go through circularization to produce the nonaromatic rings of cholesterol via a few different reaction steps into a nostril. Now, once we have Linostrual, you can see it’s getting pretty close to what cholesterol looks like.
But Nevertheless, Linostral to cholesterol still takes 18 reaction steps to get to cholesterol production. So I just wanted to show you guys just how the chemistry, how we go from simple monomers. And the monomers are actually used to form somewhat like a polymer, and that polymer goes through a circularization reaction to get cholesterol.
And it takes many, many different reaction steps to produce cholesterol. So I don’t want you guys to think it’s a very simple pathway, it’s a very complex pathway.
And one final point I want you guys to know is that many of these steps, especially from swelling through lineostrial and through cholesterol production, these reaction steps require enzymes that are located on or near to the endoplasmic reticulum interface.
So a lot of these reactions occur at the interface of the endoplasmic reticulum. Now once cholesterol has been produced, how is it stored as cholesterol Ester? I talked about cholesterol Ester or otherwise known as cholesterol Ester. So how is cholesterol actually stored as cholesterol Ester?
What reduces cholesterol quickly
Well it actually undergoes a reaction through the enzyme Acad. If it’s in the cell, if it’s in a cell it undergoes a reaction by the enzyme ACAT or ACell COA cholesterol ACell transferase or ACAT and this occurs at the er. Now what it does is it actually takes the ACIL chain from ACIL COA and adds it to the hydroxyl group of the cholesterol to form a cholesterol Ester so that’s the storage form of cholesterol.
Now if cholesterol is not in the cell, if it’s in the extracellular environment It actually is operated or acted on by a different enzyme known as LCAT which is Lechethyn cholesterol acidis rays and this occurs in the serum and it actually uses phosphatidyl choline it uses an acid group from the phosphatidl choline to attach to the hydroxyl group of cholesterol to form cholesterol Ester. Now as I mentioned before Cholesterol Ester is very important to know because approximately 65% of plasma cholesterol is actually stored as this cholesterol Ester.
Now once you have cholesterol Ester stored how does it actually go back to cholesterol? Well it actually does that by an enzyme known as cholesterol S. Rays which is very easy to remember. So cholesterol estraze actually acts on cholesterol Ester, removes the acid group and forms cholesterol again in its active form. Anyways, guys, that was a quick look at the cholesterol synthesis pathway.
FAQs
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conclusion
cholesterol synthesis occurs in our bodies through a process of turning a group of compounds called sterols into cholesterol. This process is regulated by the body to help maintain a healthy balance of cholesterol in our bloodstreams. Now that you know how cholesterol is made, make sure to keep your lipid levels in check by eating a balanced diet and exercising regularly.
