Identify the following glycerophospholipid, which is found in the nerves and spinal cord in the body, as a lecithin or cephalin, and list its components:

Question

Chemical structure of a glycerophospholipid, indicating its components and functional groups.

Accepted Answer

Welcome back, everyone. Our next problem says, consider the following glycerophosphate which is found in plant membranes. And we have a structure here. We'll go into it in a little more detail. Um As we go through our answer choices, but just a glance at the overall structure here, we have, of course, we've given the name glycerophosphate. So we look right away and see this Glycerol backbone, our three carbons there attached with tra linkages. And then we see on carbon one, we have a fatty acid on carbon two, another fatty acid which connected we have that carboxylic acid connected with that tra linkage and we have a long nonpolar carbon chain. So two fatty acid chains and then we have the phosphate group on the third carbon but attached to the phosphate group, we have the CH two ch two NH three with a positive charge on the nitrogen. And then our question asks us identify whether this is a lecithin or a cephalin and provide the components that make up this glycerol phospholipid. We have four answer choices that all start with the glycerophosphate. It is a, I'm just going to say it is a so I don't have to read that long name every time. So choice A says it is a cephalin. Its components are glycerol, linoleic acid, palmitic acid and ethanolamine. B. The glycerol phospholipid is a cephalin. Its components are glycerol, linoleic acid, palmitic acid and cline C the glycophos lipid is a lecithin. Its components are glycerol, linoleic acid, palmitic acid and ethanolamine or d the glycerophosphate is a lecithin. Its components are glycerol, linoleic acid, palmitic acid and Cole. Well, I did end up reading the whole word after all, but that's OK. We can look at this and see this question's a little less complicated than we might have thought at first with a little less for us to remember our only two choices for describing this are either sein or lessen. So we need to remember the distinction between those two and these are the most common phospholipids in cell membranes. So that helps us since we're told it's in a membrane. And the key is the group that's attached to the phosphate, the nitrogen containing group. And lecithin contain a choline group while cephalin contain either an ethanolamine group or the amino acid searing. So that's going to be our distinction there. And then notice in the components list all four answer choices, list Glycerol, linoleic acid and palmitic acid. So we don't even need to identify which fatty acid is which that's not a distinction between answer choices. It's just whether we have ethanolamine or choline So we know sine isn't there. Which makes sense because we don't see an extra um carboxylic acid group, which we would, since sine is an amino acid, we just need to distinguish which, whether it's ethanolamine or cooling. And that's fairly straightforward actually because we have two carbons, ch, two, ch two and then an NH three group. So we've got a primary amine with two carbons. So that's going to lead us to ethanolamine as our answer. And therefore a seine cline very similar structure, but you'd have a tertiary, I mean with two methyl groups on that nitrogen. So we know we have an ethanolamine. So we can go ahead and cross out choice B which has Colleen and Choice D which has choline. And then we just need to identify the one that has cephalin and that will be choice a cephalin. Whereas Choice C identifies it as a lecithin. Now, just in case you're curious here, want to be thorough our fatty acids here, our top one is linoleic acid which we notate, it has 18 carbons and two double bonds. And then our second one is the palmitic acid with 16 carbons and zero double bonds. But again, you didn't need to know that to answer the question, we just had to remember that Aming group and which category of glycerophosphate? This was so identifying this glycerophosphate and what are its components? The answer is choice. A, the glycerophosphate is a Zeppelin, its components are glycerol, linoleic acid, palmitic acid and ethanolamine. See you in the next video.

Identify the following glycerophospholipid, which is found in the nerves and spinal cord in the body, as a lecithin or cephalin, and list its components:

Verified video answer for a similar problem:

Key Concepts

Glycerophospholipids

Lecithin vs. Cephalin

Components of Glycerophospholipids