Lipids PDF

Lipids and Their Functions 8/27/24, 8:15 PM Platform | Study Fetch (00:00:12 - 00:00:23) Function of Lipids Primary function is long-term energy storage Can serve as structural functions in the cell Lipid Pr...

Lipids and Their Functions 8/27/24, 8:15 PM Platform | Study Fetch (00:00:12 - 00:00:23) Function of Lipids Primary function is long-term energy storage Can serve as structural functions in the cell Lipid Properties Hydrophobic and nonpolar Can form micelles, spherical membrane-bound containers Can form the cell membrane and other structures Classes of Lipids (00:00:45 - 00:00:58) Steroids One of the four classes of lipids Waxes One of the four classes of lipids Triglycerides Found in fats like oil and butter Used by animals for insulation and long-term storage, and by plants for energy storage Phospholipids One of the four classes of lipids Discussed further in the video (00:00:58 - 00:01:12) Triglycerides Found in fats like oil and butter Used by animals for insulation, long-term storage, and by plants for energy storage Phospholipids One of the four classes of lipids Discussed further in the video https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bc0e81bb65113fe36aa/document?go=note 1/5 8/27/24, 8:15 PM Platform | Study Fetch Triglycerides: The Body's Energy Stores (00:01:12 - 00:01:24) Triglycerides are a major source of energy for the body They can be stored in the body for long periods of time and are difficult to get rid of Triglycerides can store a large amount of energy Structure of Triglycerides (00:01:24 - 00:01:41) Triglycerides are composed of: Glycerol Three fatty acids attached to the glycerol The fatty acids can be of various types, making triglycerides a versatile energy storage molecule Saturated vs. Unsaturated Fatty Acids (00:01:41 - 00:01:55) Saturated fatty acids: Only have single bonds between carbon atoms All carbon atoms are "saturated" with hydrogen atoms Unsaturated fatty acids: Have double bonds between some carbon atoms Can still take on more hydrogen atoms due to the double bonds Structural Differences (00:01:55 - 00:02:06) Saturated fatty acids have no double bonds, so all carbon atoms are bonded to the maximum number of hydrogen atoms Unsaturated fatty acids have double bonds between some carbon atoms, leaving room for more hydrogen atoms to be added Kinks in Unsaturated Fatty Acids (00:02:06 - 00:02:20) The double bonds in unsaturated fatty acids cause kinks or bends in the carbon chain This kinked structure is an important property of unsaturated fatty acids https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bc0e81bb65113fe36aa/document?go=note 2/5  Cis vs. Trans Fats 8/27/24, 8:15 PM Platform | Study Fetch (00:02:20 - 00:02:37) Cis fats have hydrogens on the same side of the double bond, making them more "bendy" Trans fats have hydrogens on opposite sides of the double bond, making them more "straight" This difference in structure can affect the overall shape and properties of the fat molecule Formation of Trans Fats (00:02:37 - 00:02:57) Trans fats are usually formed during the production of processed foods To increase the shelf life and melting point of fats, excess hydrogen atoms are introduced into unsaturated oils This process can lead to the formation of trans fats Trans fats can contribute to the formation of low-density lipoprotein (LDL), which can lead to atherosclerosis in the arteries Omega-3 Fatty Acids (00:02:57 - 00:03:12) Omega-3 fatty acids have a double bond on the third carbon from the end, in the cis configuration Omega-3 fatty acids are often associated with health benefits, such as reducing inflammation and improving heart health Triglycerides and cholesterol are also carried by the same lipoproteins that can contribute to atherosclerosis Cis-Trans Isomers and Phospholipids (00:03:22 - 00:04:22) Cis-Trans Isomers Cis isomers have both carbons and hydrogens on the same side of the double bond Trans isomers have the carbons and hydrogens on opposite sides of the double bond "Cis" means "same" - the carbons and hydrogens are on the same side Phospholipids Phospholipids have a polar head group and fatty acid tails The head group is hydrophilic (water-loving) and the tails are hydrophobic (water-fearing) This allows phospholipids to form layers and interact with aqueous solutions Phospholipids are amphipathic, meaning they have both polar and nonpolar regions This allows them to form liposomes, micelles, and bilayer membranes "Phospholipids have a polar head group as well as uh fatty acid tails coming off uh off from them with the hydrophilic head. They have the hydrophobic tail and this allows them to form uh layers https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bc0e81bb65113fe36aa/document?go=note 3/5  interacting with an aqueous solution." (00:03:22 - 00:03:38) 8/27/24, 8:15 PM Platform | Study Fetch "And we talk about this more in the membrane section. And again, phospholipids are empathic and this means that they have a polar head and a nonpolar tail. And this allows them to form these liposomes, mi cells bilayer membranes." (00:03:38 - 00:03:53) Steroids Steroids are made up of four fused rings of carbon This makes them very nonpolar compared to phospholipids This allows steroids to easily enter membranes "All of these structures are possible because phospholipids are opic steroids are made up of four fused rings of carbon. And this makes them very nonpolar compared to things like phospholipids." (00:03:53 - 00:04:06) Waxes Waxes are a combination of a fatty acid carboxylic acid and an alcohol They are formed through a dehydration reaction "And this allows them to enter into membranes, easily waxes uh are the combination of a fatty acid carboxylic acid combined with an alcohol that will form a dehydration reaction released in" (00:04:06 - 00:04:22) Lipids: The Diverse Molecules of Life (00:04:22 - 00:04:35) Lipids are formed through the dehydration of a carboxylic acid and an alcohol, creating an ester linkage. This ester linkage is what forms an ester wax. There are four main categories of lipids: triglycerides, phospholipids, steroids, and waxes. (00:04:35 - 00:04:54) All lipids are nonpolar and therefore insoluble in water. The exception is phospholipids, which are moderately soluble in water and can form membrane- bound spheroids in solutions. (00:04:54 - 00:05:06) The primary functions of lipids are long-term energy storage, structural purposes, and hormone production. Many steroids are signaling molecules within the cell and play very important roles in the body. (00:05:06 - 00:05:16) Lipids are a diverse and important class of molecules with a variety of functions in the body. https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bc0e81bb65113fe36aa/document?go=note 4/5  Triglycerides 8/27/24, 8:15 PM Platform | Study Fetch Key Points: Composed of a glycerol backbone with three fatty acid chains attached Serve as the main form of long-term energy storage in the body Can be saturated (no double bonds) or unsaturated (contain double bonds) Phospholipids Key Points: Composed of a glycerol backbone, two fatty acid chains, and a phosphate group Form the basic structure of cell membranes Amphipathic - have both hydrophobic and hydrophilic regions Steroids Key Points: Composed of four fused hydrocarbon rings Include cholesterol, hormones (e.g., testosterone, estrogen), and bile salts Serve as signaling molecules and have structural roles Waxes Key Points: Composed of a long-chain alcohol esterified with a long-chain fatty acid Provide a protective, waterproof coating on plant and animal surfaces Examples include beeswax, plant cuticles, and mammalian fur/skin Conclusion:Lipids are a diverse and essential class of biomolecules with a wide range of functions in the body. Understanding the different types and their properties is crucial for students studying biochemistry and biology. https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bc0e81bb65113fe36aa/document?go=note 5/5