In this video, we're going to do a review of all the lipids that we've covered so far by analyzing our comprehensive final lipid map. And so what you see here on this page is our comprehensive final lipid map, which you'll notice looks a lot like the lipid map that we showed you guys early on in this lesson on lipids. And really the big differences are that here we have some additional images and some additional text to help you guys remember important features about these lipids. And so the idea here is that you can use this comprehensive final lipid map here to complement your studying and help remind you of important features about these lipids. Alright. So that being said, let's go on and get started with our comprehensive final lipid map. And so, we know that lipids are immediately branched into 2 groups, The fatty acid base lipids over here in the left branch, and the isoprene based lipids over here with the right branch. And so we're gonna review the fatty acid base lipids first. So recall that fatty acids are just long hydrocarbon chains like this one with a carboxylic acid group at the end. And there are many different types of fatty acids, including saturated, unsaturated, and omega fatty acids, which recall omega fatty acids are essential and required in the diet, and they're commonly found in fish. Now recall that the alpha carbon of a fatty acid is the carbon atom that is adjacent to the carboxylic acid carbon over here. And recall that the omega carbon atom is the carbon atom that is furthest away from the carboxylic carbon atom over here. And also don't forget about the nomenclature of these fatty acids, the shorthand naming system specifically. Which all we need to do is count the total number of carbon atoms in the fatty acid, which in this fatty acid, there are 16 carbon atoms. And then count the total number of double bonds, which in this fatty acid, there's 1 double bond in the hydrocarbon chain. And then indicate the position and location of that double bond with a delta exponent. And so counting from the carboxylic acid carbon over here, the double bond, notice, appears at carbon number 8. And so the shorthand naming system for this fatty acid is 16 1 Δ 8 . Now there are really 4 major classes of fatty acid based lipids, which we have as glycerolipids, sphingolipids, waxes, and eicosanoids. Now recall that the Glycerolipids are literally lipids with a glycerol molecule as the form and the fatty acids that are in these glycerol lipids are typically ester linked. And there are really 2 types of glycerolipids that we had talked about. The triacylglycerols and the glycerophospholipids. Now the triacylglycerols with the tri prefix have 3 fatty acids that are Ester linked to the glycerol molecule. And we talked about these functioning specifically as long term energy storage molecules. And so just like batteries act as long term energy storage, these triacylglycerols also act as long term energy storage. Now, the glycerophospholipids notice are falling into this pink box that we have here, which are labeling our phospholipids and phospholipids are just lipids with phosphate groups that are covalently attached. And so, glycerophospholipids are specific types of phospholipids that have a glycerol backbone as the platform. Recall that phosphatidates are the simplest glycerophospholipid because they do not have a variable head group attached. And simply by attaching all of these different variable head groups here, we can get different classes of Glycerophospholipids. And the main, indicator of a Glycerophospholipid is this prefix phosphatidyl, which is saying that it has the phosphatidate backbone and some varying branching variable head group. Now what's important to note is that phosphatidylcholine is actually the most abundant Glycerophospholipid found in membranes. And so what you'll notice is that these phospholipids here are being branched into these biological membranes, and we'll talk more about biological membranes later in our course. So moving on to the sphingolipids which is our second type of fatty acid based lipids. These are lipids that have a different platform. Instead of having a glycerol molecule as the platform, sphingolipids have a sphingosine molecule as the platform. And sphingosine molecules will actually attach their fatty acids via amide linkages instead of ester linkages. And so the amide linkage here is key, which is why it's here in our text. Now there are 2 major types of sphingolipids that we had talked about, the sphingophospholipids and the sphingoglycolipids. The sphingophospholipids are another type of phospholipid that again use a different platform, which is the sphingosine platform, and we talked about one specific sphingophospholipid, which was sphingomyelin, and that is commonly found in the myelin sheath of the membranes that surround our axons of our nerve cells. And so here we have that image of our axon of our nerve cell to help remind you that sphingomyelin are found in the myelin sheath. Now the sphingoglycolipids are glycolipids with a sphingosine backbone. Now, be careful not to confuse the prefix glyco with the prefix glycero. Glycero, of course, means that it has a glycerol platform, and glyco is referring to carbohydrates or sugars. And so, these are our glycolipids, lipids that are covalently attached to sugar units. Cerebrosides only have one single sugar unit attached, and these are commonly found in our brains. And, globocytes, they have 2 or more sugar units. And then gangliosides are a specific type of globocyte where they have a complex oligosaccharide attached that have multiple sugars and a sialic acid residue, which is this orange residue that we're labeling here, commonly NEU 5AC. Now these gangliosides, they are associated with Tay Sachs disease. And so if there are metabolism defects with the gangliosides that will lead to this neurological disease called Tay Sachs disease. So the next fatty acid base lipid that we have are the waxes and waxes we know are fatty acid chains or FA for short and long chain alcohol groups, or LCA for short. And, the fatty acid and long chain alcohols are ester linked together to create the wax. And the wax that we had talked about in our previous lesson videos are, was beeswax. So, that is why we have that here. Now the 4th and final type of fatty acid base lipids that we have are the eicosanoids. And recall that the prefix eicosi is, a Greek prefix that means 20. And so eicosinoids are derived from c 20 polyunsaturated fatty acids, like arachidonic acid, which is, again, a fatty acid itself and explains why eicosanoids are fatty acid based lipids. And there are 3 different types of eicosanoids. There are the prostaglandins, the thromboxanes, and the leukotrienes. Recall that the p in the prostaglandins reminds us that it has a cyclopentane ring, like the one that we see down below. And prostaglandins, we said, have lots and lots of different types of functions. But one of their primary functions includes the regulation of pain, inflammation, and fever.
10. Lipids
Comprehensive Final Lipid Map
10. Lipids
Comprehensive Final Lipid Map - Online Tutor, Practice Problems & Exam Prep
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Comprehensive Final Lipid Map
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