Draw the structure of a triacylglycerol made from two molecule...

Question

Draw the structure of a triacylglycerol made from two molecules of myristic acid and one molecule of linolenic acid.

Accepted Answer

All right. Hello everyone. So this question says that a tri ao glycerol consists of two molecules of stric acid and one molecule of linoleic acid draw its structure. So for this question, right, recall first and foremost that a tri ao glycerol, otherwise known as a triglyceride is composed of a Glycerol backbone, which we'll discuss the structure of in a moment as well as three fatty acid chains. So of the three fatty acids, two are going to be stric acid and one is going to be linoleic acid. So before we go ahead and talk about the structure itself, let me just go ahead and scroll down to where I pre drew the structures of the fatty asses in question. And the reason I did so primarily was to just save a little bit of time and make sure that I have all the carbons here. So now that they're up on the screen, our first is going to be stric acid, which is a saturated fatty acid consisting of a total of 18 carbons, one of which is the carboxylic acid. Now on the bottom, we have linoleic acid, which I previously spelled wrong. So let me fix that, which just so happens to be a poly unsaturated fatty acid consisting of a total of 18 carbons. Now, we have three carbon carbon double bonds located at positions 9, 12 and 15 on the carbon chain. So now that we have a sense of our fatty acid components, let's recall the structure of Glycerol. Now, glycerol, if you recall is a three carbon molecule where each carbon has a hydroxy group attached to it. So here each hydroxy group, each alcohol group from Glycerol reacts with the carboxylic acid group of each fatty acid to create an er bond. So really there are two possibilities here when it comes to the structure of the complete try ao glycerol. Now, the first possibility is that we have our one molecule of stric acid connecting to carbon number one of glycerol with both equivalents of linoleic acid connecting to carbons two and three. And then our second possibility is where cric acid instead bonds or binds to carbon two of Glycerol and our linoleic acids connect to carbons one and three respectively. So lets go ahead and start with our first possibility, our first isomer. So to go ahead and showcase this new era bond, what I'm going to do is erase the hydrogens of each hydroxy group in Glycerol. And I'm also going to go ahead and remove the hydroxyl groups of each carboxylic acid from the fatty acids themselves. So here what I'm going to do first is take my carbon chain here for stric acid and move that. Now two carbon number one of glycerol. And so I'm going to move this here attached now to oxygen and I recognized that now I just ran out of space. All right. So I had to pause the recording just to make sure that everything fits. But now it does, right. We have our one equivalent of stric acid now connecting to the first carbon of our Glycerol backbone. So up on the screen, I have the structure of one carbon chain for linoleic acid. So what I'm going to do is just duplicate it because there are going to be two in each isomer. So here is one attaching to carbon tube, glycerol and here's the other attaching to carbon three glycerol. So this completes our first try Azo Glycerol. And so now recall that we have a second isomer to consider. So let's go ahead and draw that one as well. So first, I am going to start by drawing out our Glycerol backbone. Here's the oxygen of each hydroxy group. And I realized that I just put three hydrogens on carbons, one and three instead of two. So let me just fix that. That's better. All right. So now we have the oxygens of our hydroxy groups and now let's go about drawing out our 2nd and 3rd ISOS sorry, just our second isomers, we only have two. So just to go ahead and re summarize in our second isomer. We would have our one stric acid connecting to carbon two glycerol and are linoleic acids connecting to carbons one and three. So here I have a copy of our stric acid chain. So ill just be moving that over now to our second position. And so now I'm going to go ahead and pause the recording for just a moment to add the carbon chains of are linoleic acids, two positions, one and three of glycerol. All right. So now there you have it, our two tri ao glycerol isomers have now been completed. And so with that being said, if you watch this video all the way through, thank you so very much for doing so. And I hope you found this helpful.

Draw the structure of a triacylglycerol made from two molecules of myristic acid and one molecule of linolenic acid.

Key Concepts

Triacylglycerol Structure

Fatty Acids

Esterification Reaction

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