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10. Lipids



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in this video. We're going to introduce waxes now before we get started. Let's first take a look at our lipid map to make sure we're all on the same page. And, of course, we know that we're currently exploring the fatty acid based lipids. And already in our previous lesson videos, we've explored the glycerol lipids as well as the swing go lipids. And so now we're talking about the waxes, which are again, another type of fatty, acid based lipid. And so waxes are really just defined as fatty acid base lipids that have a long chain fatty acid that is Esther linked to a molecule that used to be, ah, long chain alcohol. And so, if we take a look at our image down below, over here on the left hand side, notice we're showing you the general formula for a wax. And that is a fatty acid molecule that is Esther linked here to a long chain alcohol or a molecule that used to be a long chain alcohol. Because it's alcohol group here is actually going to react to become part of the Esther. And so if we take a look at our image over here on the right hand side, we can see the equation for a wax at the top, and that is again a fatty acid molecule. Ah, long chain alcohol and combining the two gives us the wax. And so, for instance, if we take the fatty acid pal Mitic Acid and this long chain alcohol group here one try a content all and through a dehydration synthesis reaction here were able to Esther link the two molecules and together when these are Esther linked in this way, this creates our wax, and this specific wax is called Try a Contin oil pal mutate, which is really just the main predominant component of bees wax. And so here we have an image of bees. And so one thing to note about thes waxes is that because they have such long, long hydrocarbon chains, like what we see over here, these are vastly, um, non polar tales, and any polar groups that they have are going to be quite weak. So the week polar groups that are on a wax are going to be overpowered by the long non polar tail, so overall waxes are still going to be non polar hydrophobic and insoluble. Also, waxes tend to have relatively high melting points, which means that they're going to typically be solids at room temperature. Now, in terms of the functions of waxes, they can have a large variety of functions, and this includes dual waterproofing in terms of keeping water out and keeping water inside of something. Also, they can act as protective coats, and they're commonly used in lotions, ointments and polishes. And so, if we take a look at our image down below, you can see that, uh, it's true that this bees wax eyes used in bees, Burt's bees, bees wax, lip balm and so, which will also notices. We've got this image of a plant here because many plants produce oils on their leaves in order to help protect, give them a protective coating and toe, help waterproof them in terms of helping to keep water inside so that they don't dehydrate too much. And so this here concludes our brief introduction to waxes, and we'll be able to get some practice in our next couple of videos, so I'll see you guys there

Which of the statements regarding waxes is FALSE?

A)  Waxes generally have melting points above room temperature.

B)  Waxes are soluble molecules in water. 

C)  Waxes are used as protective coatings against dehydration and parasites.

D)  Waxes are esters of long-chain fatty acids and long-chain alcohols.