Intro to Lipids - Video Tutorials & Practice Problems
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Intro to Lipids Concept 1
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Everyone in our intro to lipids. Let's first talk about where is this word lipid derived? We're gonna say here that it, it's derived from the word lipo, which is a Greek word meaning fat. Now, when we talk about lipids themselves, they represent hydrocarbon based biomolecules that are hydrophobic, meaning they're in cable in water due to being nonpolar. Now we're gonna say that they are very diverse structurally and functionally. We'll see how they can be broken down further from lipids. Now, one of these breakdowns are fatty acids, fatty acids are long unchained hydrocarbon chain with a carbolic acid at one end. And we're gonna say here that lipids can be categorized based on the presence or absence of fatty acids. If we take a clear look at, take a look here at this chart or breaking down lipids, we have our steroids to the right steroids are indicative of these four few cells. Steroids themselves can be broken down into cholesterol bio aids and steroid hormones. When we get to the steroids, sexual go in greater detail on these other three breakdowns. Now, fatty acids themselves represent this portion here. Again, it's a long hydrocarbon chain with a carbolic acid at the end, it can be broken down further into four other things. We have our waxes which are gonna give us our alcohol and fatty as al alcohol esters and fatty acids involved. We're gonna have our, our glycerol lipids. This can be broken down into our trio glycerol, which is just a Glycerol molecule that has three fatty acids chains branched off of it. Next, we have our glycophos lipids which are grouped together with our spino myelins. Now, here, this is also part of our spino lipids here, which are also broken down into our glycol lipids. Now, here, if we take a look at the similarities of what's in the dotted purple box, these are our phospholipids. So phospho phosphate group and our lipids together, we can see that there are some similarities. Both of them have our phosphate group connected to an amino alcohol. Again, this is just a quick overview of, of the main components of this group. We'll go in greater detail when we get to these sections. So they both have this in common. They both also have a fatty acid in common. The difference is our glycophos lipid also has an additional fatty acids and all of it's connected to a glycerol molecule over here though we have our sphingosine, which is our base group and our fatty acids and phosphate group and amino acid alcohols are attached to that. Finally, we have our glycol lipids here which we have also a stingy, but we have a fatty acid and a sugar that's attached. Finally, our fourth group, this is a ICAO which is represented by this long carbon chain as well, but it has portions of pi bonds. So it has unsaturated portions. And then at the end, again, we have a carbolic acid. So as you can see, lipids form the umbrella term for all of these diverse groups that have some similarities, but also have some great differences when you're comparing different groups to one another. So as you go through this idea of lipids, we're gonna cover these different types of characterizations.
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Intro to Lipids Concept 2
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Now, remember we said that lipids can be very diverse structurally and functionally. Now, here, some primary lipid functions include. Here we have our energy source and storage when it comes to certain types of them. Next we're gonna have here is insulation and protection. So here this person shivering, these can help provide insulation to keep us warm. Next, we have bi bios signalling, we can utilize them to communicate between different mo biomolecules within a living system. And then finally, here we have our cell membrane structure. Some of these diverse forms of lipids form integral parts of different types of cells. In terms of their cell membranes, they help with the uh transportation of nutrients into the cell. It helps with the passage between membranes of ions and different types of helpful components for any type of biological system, right? So these are just some of the main primary functions of a lipid.
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Intro to Lipids Example 1
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Which of the following statements about lipids are not true. Steroids are a class of lipids which do not contain any fatty acids. Yes, that's true. Remember the first branching off of lipids are fatty acids and are steroids. If steroids contain fatty acids, they wouldn't be different from fat. Um from fatty acids themselves. All lipids are insoluble in nonpolar solvents but soluble in polar solvents. So remember these lipids, many of the lipids contain fatty acids which are long carbon chains. Those long carbon chains make them nonpolar, which would mean that they are soluble in nonpolar solvents and insoluble in polar solvents. This statement here is false. So this is our answer. If we look at our other options, certain lipids play an important role in components of biological membranes. That is one of the primary lipid functions that do exist. So this is true lipids contain large number of nonpolar carbon hydrogen bonds, making them overall nonpolar. This is true. A lot of these lipids contain fatty acids chains which are just carbon hydrogen bonds, which are nonpolar. So overall they're nonpolar steroids themselves also contain fused carbon rings. Those are also sites of being nonpolar So here, the only statement that's false will be option B.