In this video, let's talk about waxes. Now waxes are simple lipids composed of a long chain alcohol and a long chain fatty acid. The fatty acid and the alcohol are attached by an ester bond. If we take a look here, this part is our ester bond, where we have our carbonyl connected to an oxygen, and then here we have our long chain alcohol. And then over here on this side, we have our fatty acid. Remember that we have our lipids, which are broken down into our fatty acids and steroids. Underneath fatty acids when we break it down further, we have our waxes. We also have these three other classifications that lie below fatty acids, but we're not concerned with them for now. For right now, we're looking at waxes themselves, which again, we have an ester bond connecting together our fatty acid and our long chain alcohol. Now, here we're going to say that waxes possess repellent properties. And we're going to say they form protective coatings on feathers of birds and leaves of plants. So, just remember when it comes to waxes, they are a further classification, a more specific classification of fatty acids themselves. And when we talk about them, we're looking at an ester bond connecting a fatty acid and a long chain alcohol.
Waxes - Online Tutor, Practice Problems & Exam Prep
Waxes Concept 1
Video transcript
Waxes Example 1
Video transcript
For this example, it says, provide a structure of beeswax. It contains myricyl alcohol and palmitic acid. So step 1 says, draw the structure of the alcohol in its condensed form, as well as the fatty acid. We're going to place an OH from the alcohol next to the carboxyl group of the fatty acid. Now, let's just do that first. The alcohol is CH3, and we're going to say here that it has 29 of these CH2 groups. We're going to do 28 of them together. The 29th one, we're going to have it branch off, and then it's connected to the OH group.
Now we need to draw the fatty acid, which is palmitic acid. Palmitic acid represents a saturated fatty acid. And if we recall our memory tool 1, it is that Lori's Mystic Palace Stores Art. Here, the mnemonic PALIS stands for palmitic acid. This mnemonic starts at 12 carbons and goes up to 20. And we have carbons 14, 16, 18. So, palmitic acid is a fatty acid that's saturated and it has a total of 16 carbons. The first carbon is part of the carboxylic acid, so that's 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16. Okay. So that's 16. So we've done that part.
Now instead of OH on alcohol, we're just gonna draw an O; this is going to help later on when we connect these two together, and we're going to say, do not draw OH on fatty acid. So let's remove this OH. We have these two fragments.
Step 2 is we're going to form the Ester Bond. So we're going to draw a bond between the oxygen of the alcohol and the carbonyl carbon of the fatty acid. Connect these two together, this oxygen with this carbonyl carbon here, and we'll have our beeswax. So let's write this out.
We have CH3 connected to 20 of these CH2s, connected to 1 more CH2, then O, which is going to be connected to the carbonyl carbon. So remember it's 16 carbons, so 2, 4, 6, 8, 10, 12, 14, 16. So that's 16. So this would represent our beeswax. We've combined the alcohol with our saturated fatty acid in order to make this particular type of wax. They're connected together through an ester bond.