Waxes are fatty acid-based lipids formed by ester linking a long-chain fatty acid to a long-chain alcohol. They are characterized by their nonpolar, hydrophobic nature and high melting points, making them solid at room temperature. Waxes serve various functions, including waterproofing and protective coatings, commonly found in plants and products like lotions and ointments. An example is triacontinoypalmitate, a major component of beeswax, formed through dehydration synthesis of palmitic acid and triacontinol.
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Waxes
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Video transcript
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 glycerolipids as well as the sphingolipids. 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 based lipids that have a long chain fatty acid that is ester linked to a molecule that used to be a 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 ester linked here to a long chain alcohol or a molecule that used to be a long chain alcohol, because its alcohol group here is actually going to react to become part of the ester.
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, a long chain alcohol, and combining the two gives us the wax. And so for instance, if we take the fatty acid palmitic acid and this long chain alcohol group here, one triacontinol, and through a dehydration synthesis reaction here, we're able to ester link the two molecules. And together when these are ester linked in this way, this creates our wax. And this specific wax is called triacontinoypalmitate, which is really just the main predominant component of beeswax.
And so here we have an image of bees. And so one thing to note about these waxes is that because they have such long, long hydrocarbon chains like what we see over here, these are vastly nonpolar tails, and any polar groups that they have are going to be quite weak. So the weak polar groups that are on a wax are going to be overpowered by the long nonpolar tail. So overall, waxes are still going to be nonpolar, hydrophobic, and insoluble. Also, waxes tend to have relatively high melting points, which means that they are going to typically be solids at room temperature.
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. What you'll also notice is 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 to 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.
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Problem
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.
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.
Here’s what students ask on this topic:
What are waxes in biochemistry?
Waxes in biochemistry are fatty acid-based lipids formed by ester linking a long-chain fatty acid to a long-chain alcohol. They are characterized by their nonpolar, hydrophobic nature and high melting points, making them solid at room temperature. Waxes serve various functions, including waterproofing and protective coatings, commonly found in plants and products like lotions and ointments. An example is triacontinoylpalmitate, a major component of beeswax, formed through dehydration synthesis of palmitic acid and triacontinol.
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What is the chemical structure of waxes?
The chemical structure of waxes consists of a long-chain fatty acid esterified to a long-chain alcohol. The general formula can be represented as: where is the long-chain fatty acid and is the long-chain alcohol. For example, in beeswax, the fatty acid palmitic acid (C16H32O2) is esterified to the alcohol triacontanol (C30H62O), forming triacontinoylpalmitate.
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What are the functions of waxes in nature?
Waxes serve several important functions in nature. They provide waterproofing, helping to keep water out and retain moisture within organisms. For example, plants produce waxes on their leaves to prevent dehydration and protect against environmental stress. Waxes also act as protective coatings, shielding surfaces from physical damage and microbial attack. Additionally, they are used in various products like lotions, ointments, and polishes due to their hydrophobic properties and ability to form a protective barrier.
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Why are waxes hydrophobic and insoluble in water?
Waxes are hydrophobic and insoluble in water due to their long hydrocarbon chains, which are nonpolar. These nonpolar tails dominate the overall structure, making waxes nonpolar and thus unable to interact favorably with water molecules, which are polar. Any polar groups present in waxes are weak and are overpowered by the extensive nonpolar regions, reinforcing their hydrophobic nature and insolubility in water.
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What is the role of waxes in commercial products?
In commercial products, waxes play a crucial role due to their hydrophobic and protective properties. They are commonly used in lotions and ointments to create a barrier on the skin, preventing moisture loss and providing a protective layer. Waxes are also used in polishes to give surfaces a shiny, protective coating. Their high melting points and solid state at room temperature make them ideal for these applications, ensuring durability and effectiveness.
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