Waxes - Online Tutor, Practice Problems & Exam Prep

Waxes are simple lipids formed from long-chain alcohols and fatty acids, connected by ester bonds. They belong to the hydrolyzable lipid group, which can be broken down. Waxes exhibit water-repellent properties, providing protective coatings on bird feathers and plant leaves. Understanding waxes is essential in the study of lipids, which are categorized into hydrolyzable and non-hydrolyzable types, highlighting their significance in biological systems.

Waxes Concept 1

Hey everyone. So in this video, we're going to take a look at waxes. Now remember, waxes represent a portion of our overall ideal lipids that are hydrolyzable. Waxes themselves are simple lipids composed of a long-chain alcohol and a long-chain fatty acid. If we take a look here, we can say that a fatty acid and alcohol are attached by an ester bond. So if we take a look here, we have our ester bond because we have this carbonyl connected to an oxygen, connected to another carbon which is part of our long-chain alcohol, and we have our fatty acid on this end. This ester bond here, it can be broken, which is why we're going to say that our waxes belong to our hydrolyzable group of lipids. If we look here, remember, lipids are broken down into what's hydrolyzable and what's not, and waxes would fit here. They themselves again are long-chain alcohol with a fatty acid. We also have within this subset our Glycerolipids and our Sphingolipids. We're going to say here that waxes, well, they possess what we call water repellent properties. And we're going to say they form a protective coat or protective coatings on feathers of birds and leaves of plants. So it has this repellent nature. Right? So just remember when we're talking about waxes, this is just one of our 3 groups that represent hydrolyzable lipids.

Waxes Example 1

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 group of alcohol next to the carboxyl group of the fatty acid. Now, let's just do that first. So, here acid 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. And we're going to say here that LORI, lmPSandA, PALIS stands for palmitic acid. This memory tool starts off at 12 carbons and goes up to 20. And we're going to have 14, 16, 18. So, palmitic acid is a fatty acid that's unsaturated 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 it says instead of OH on alcohol, we're just going to draw an O, this is going to help later on when we connect these 2 together, and we're going to say, do not draw OH on fatty acid. So let's remove this OH. So we have these 2 fragments. Step 2 is we're going to form the Ester Bond. So we're going to draw a bond between the O of the alcohol and the carbonyl C of the fatty acid. So connect these 2 together, this oxygen with this carbonyl carbon here, and we'll have our beeswax. So let's write this out. So we have CH₃ connected to 28 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 unsaturated fatty acid in order to make this particular type of wax. They are connected together through an ester bond.

Structure of component of spermaceti wax is given below. If it gets hydrolyzed, draw structures of molecules it would produce.

In this practice question, it says, the structure of a component of spermaceti wax is given below. If it gets hydrolyzed, draw structures of the molecules it will produce. So if we take a look here, this is an Ester. Right? Because we have our Carbonyl group, oxygen connected to another carbon. So we're basically hydrolyzing an ester. If we're going to hydrolyze this, we just need to remember what happens when our Ester undergoes hydrolysis. Remember, esters are carboxylic acid derivatives. So if it undergoes hydrolysis, it will produce back the parent carboxylic acid. We have 1, 2, 3, 4, 5, 6, 7. We'd have our carboxylic acid being formed. Right? We're hydrolyzing. We're cutting the ester bond. Plus, this portion here just becomes our alcohol again. So remember this is a callback to when we talked about hydrolysis of esters. Esters being carboxylic acid derivatives. When they undergo hydrolysis, they would recreate the parent carboxylic acid plus an alcohol. These will be our 2 components that we will create from the hydrolysis of our original wax.

Here’s what students ask on this topic:

What are waxes in organic chemistry?

Waxes are simple lipids composed of long-chain alcohols and long-chain fatty acids, connected by ester bonds. They belong to the hydrolyzable lipid group, meaning they can be broken down by hydrolysis. Waxes exhibit water-repellent properties and are commonly found as protective coatings on bird feathers and plant leaves. Understanding waxes is crucial in the study of lipids, which are categorized into hydrolyzable and non-hydrolyzable types, highlighting their significance in biological systems.

How are waxes formed in organic chemistry?

Waxes are formed through a condensation reaction between a long-chain fatty acid and a long-chain alcohol. This reaction results in the formation of an ester bond, where the carbonyl group of the fatty acid reacts with the hydroxyl group of the alcohol. The general reaction can be represented as:

$R_1-\mathrm{COOH}+R_2-\mathrm{OH}\to R_1-\mathrm{COO}-R_2+H2O$

Here, R₁ and R₂ represent the long hydrocarbon chains of the fatty acid and alcohol, respectively.

What are the properties of waxes?

Waxes possess several notable properties. They are hydrophobic, meaning they repel water, which makes them excellent for forming protective coatings. This water-repellent nature is why waxes are found on bird feathers and plant leaves. Additionally, waxes are solid at room temperature due to their long hydrocarbon chains, which contribute to their high melting points. They are also relatively inert, making them stable and resistant to degradation under normal conditions.

What is the role of waxes in biological systems?

In biological systems, waxes play crucial roles primarily due to their water-repellent properties. They form protective coatings on the feathers of birds, helping to keep them dry and insulated. Similarly, waxes coat the leaves and stems of plants, reducing water loss through evaporation and providing a barrier against pests and pathogens. These protective functions are vital for the survival and efficiency of various organisms in their respective environments.

How do waxes differ from other lipids?

Waxes differ from other lipids in their structure and function. They are composed of long-chain alcohols and fatty acids linked by ester bonds, whereas other lipids like triglycerides consist of glycerol and three fatty acids. Waxes are hydrolyzable, meaning they can be broken down by hydrolysis, unlike non-hydrolyzable lipids such as steroids. Functionally, waxes are primarily used for protection and water repellency, while other lipids may serve as energy storage, structural components of cell membranes, or signaling molecules.