Compare the structures and functional groups of arachidonic ac...

Question

Compare the structures and functional groups of arachidonic acid and prostaglandin PGE₁.

Accepted Answer

Hello, everyone. Here's your next question. Which statements about the difference in the functional groups of Arachidonic acid and PGF two are correct statement. One, Arachidonic acid contains four double blonds. While PGF two contains two double blonds. Statement two PGF two has a cyclops ring as part of its structure. Whereas Arachidonic acid is a straight chain fatty acid with no rings. Statement three PGF two has three hydroxyl groups. Oh that Arachidonic acid does not have that statement. Four PGF two has a ketone group while Arachidonic acid does not. So before we really thoroughly look at these statements, let's think about some generalities that might be good to know about these two molecules. So the thing that we always should keep in mind, PGF two is a Prostaglandin and Prostaglandins are all synthesized from their precursor or raccoon acid. So we'll put precursor by Arachidonic acid and a key part of the structure of all the prostaglandins is that they all have a cycling ring as you know, kind of the their characteristic structure within two long hydrocarbon tails. So prostaglandins, so they have this cop pentane ring and then I'm just putting a zig zag here because I'm not going to draw the specific structure, but this is their general structure. All of them with a psycho ring. Arachidonic acid has no rings. So we can already see that statement two is correct PGF two is cyclops ring. So do all prostaglandins as part of its structure. Whereas Arachidonic is a straight chain fatty acid with no rings. So we know fatty acid is a long hydrocarbon chain with a carboxylic acid group. So it, and what we should know is that in Raonic acid, the carboxylic acid group is its only functional group. So we'll put coo H is only functional group. But another thing to know about the structure, it is a straight chain fatty acid. But looking at the shape of the structure of the prostaglandin in general, uh Aroon acid has four Ciss double bonds. And so that gives it a sort of bend. And you can see how it could be a precursor of our Prostaglandin. So you can see how the general shape here can be converted into a cyclops ring with those two tails on it that the prostaglandins have. So we see it has four cyst double bonds, the Raonic acid, which as we saw statement one says in there, a Raonic acid contains four double bonds. So that is true. And then PGF two, we don't even need to know the specific structure. The subscript two specifically tells us there are two double bonds. PGF one for instance would have one double bond, pge 22 double bonds. So we have that information right? In the name statement, one also correct then statement three says PGF two has three hydroxyl groups that Arachidonic acid does not have. Well, we know Arachidonic acid does not have that because we've said it's only functional group, we say only functional group is carboxylic acid. Whereas PGF two, it has three hydroxyl groups. This is something again, we don't need to know the specific structure but to keep the different prostaglandins straight, there's PGF prostaglandins and PGE. So PGF prostate glands are known because they have 30 groups. So whether it's PGF one or PGF 22 of them are on the cyclops ring and then one out on one of the chains, then there are PG prostaglandins. So write PGF means three hydroxyl groups, 30 groups. Pge Prostaglandins have a key to plus two hydroxyl groups. So on the cyclops ring in PGES, one of the hydroxyl groups is instead a ketone. So statement three also correct. Then we get to chase statement four. Well, you should know by what we just said. It says PGF two has a ketone group while Raccoon acid does not or Adon acid doesn't have a ketone group other than uh again, same with hydroxyl group, both AC O or C double bond O and an oh are part of the carboxylic acid group. But you give it its own name. It's a carboxylic acid. And as we just discussed, it wouldn't be PG two that has a key to Pge Prostaglandins have ketones. So statement four is our one incorrect statement. So the statements about the difference in the functional groups of Arachidonic acid and PGF two that are correct. Our statements 12 and three. See you in the next video.

Compare the structures and functional groups of arachidonic acid and prostaglandin PGE₁.

Key Concepts

Arachidonic Acid Structure

Prostaglandin PGE₁ Structure

Functional Groups in Lipids

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Compare the structures and functional groups of arachidonic acid and prostaglandin PGE1.

Key Concepts

Arachidonic Acid Structure

Prostaglandin PGE₁ Structure

Functional Groups in Lipids

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Compare the structures and functional groups of arachidonic acid and prostaglandin PGE₁.