Fatty Acid Nomenclature

in this video, we're going to begin our lesson on fatty acid nomenclature. Now, before we get started with the nomenclature, I first want to point out this modified version of our original lipid map. And this is here just to remind you guys that we're still talking about fatty acids here in this lesson, and we have not yet moved on from talking about fatty acids and also a reminder that later in our course, we'll talk about the ISO preens. But this is on Lee after we finished talking about the fatty acids and all of our fatty acid based lipids. But for now we're talking about the fatty acids and specifically the nomenclature of these fatty acids, and it turns out that there's actually several fatty acid nomenclature systems. There's a common naming systems, such as Oleic acid here, for instance, naming this fatty acids. There's also a systematic naming system or nine Octa Deccan Oleic acid, again naming the same exact fatty acid. And then there's also a short hand naming system, which is 18 1 Delta nine and again, this is just another name for the same exact fatty acid. And so in our next video. We're going to talk specifically about the shorthand naming system, since this is likely going to be the nomenclature system that your professors want you guys to know. And so I'll see you guys in that next video where we introduced the shorthand naming system for fatty acids.

In this video, we're going to introduce the shorthand naming system for fatty acids, and so fatty acids can be assigned shorthand names using the following four step process that we have number down below as 123 and four. And Step four is on Lee if it's necessary, and then notice that in our example we have a fatty acid that we can use to practice this force that process. And so the very first step is simply to count the total number of carbon atoms in the fatty acids. And so if we count the total number of carbon atoms in this fatty acid down below, you'll count that there are 18 carbon atoms now. The second step is simply to count the total number of double bonds that are present in the entire fatty acid, if there are any. And so when we take a look at this fatty acid down below noticed that there are actually two double bonds present in the hydrocarbon chain. And so what that means is we can indicate here that there are two double bonds. However, if there were zero double bonds, then we would just put zero for this number Now. Step number three is simply to separate the first number here and the second number here by a colon. So we separate them by a colon. So that way we get the total number of carbon atoms, uh, separating by a colon, the total number of double bonds. And so we could go ahead and do that down below here. So what we have is 18 total carbon atoms and to total double bonds here and here. And then, of course, the fourth step is on Lee. If it's if it's necessary and that is, if there actually are double bonds present, then you have to go to step number four. But if there were zero double bonds, then we would be done, and we would not have to go to step before. So Step number four is on Lee to indicate the presence and location of any double bonds. And you do that by using a superscript on the Greek letter delta. And so this triangle that you see right here is the Greek letter Delta and the superscript is really just a exponents. So the superscript or the exponents really just indicates the lowest numbered carbon that's forming each double bond. And so when we take a look at our fatty acid down below, we want to indicate the presence and location of these two double bonds. And so again, the way that we do that is we have to start by numbering the carbon atoms. And we know that we usually we number the carbon atoms starting from the carb, oxalic acid, carbon. And so this would be carbon one theatric a carbon here, which is the one adjacent to the car box. Cilic Acid, Carbon It's gonna be carbon too. This is carbon 345678 And then notice that carbon number nine right here is the first carbon atom of this double bond. So it's the lowest numbered carbon off forming this double bond. And so that means that up here in the exponents for the Delta, we're gonna wanna put a nine here to indicate the position of this double bond. And so, of course, this carbon is gonna be 10. This will be 11. This one will be 12 and noticed that the 12 years the first carbon of this second double bond, and it's the lowest numbered carbon, indicating the presence of the second double bond. So the next exponents here, which is separated by a comma, is gonna be 12. And really, that is it. This is the complete shorthand naming system. Um, for this fatty acid right here. And the common naming system for the Saudi acid is Linda Lake acid. And so we'll be able to get practice a utilizing this shorthand naming system in our next couple of practice problems. So I'll see you guys there.