How does the structure of lipids relate to its function? | Socratic
Illustrate different types of lipids and relate their structure to their role in biological systems. In this outcome, we will discuss lipids, or fats, and the role they plan in. Lipids play many roles in cells, including serving as energy storage (fats/ ω-3 fatty acids are lesser so. Figure - Structure of a fat/oil. Fats/oils . a vinyl ether linkage at position 1 of glycerol, in contrast to other. In biology and biochemistry, a lipid is a biomolecule that is soluble in nonpolar solvents. Fatty acids, or fatty acid residues when they are part of a lipid, are a diverse group This in turn plays an important role in the structure and function of cell of one or more sugar residues attached to glycerol via a glycosidic linkage.
Cell-cell communication Steroids are a group of lipids involved in cellular communication. A number of steroids are hormones and are important for many processes in the body including growth, sexual development, regulating metabolism and immune defense. Structure of lipids There is a huge variety of different lipids and the chemical structure varies between each of them.
Because of this it is difficult to outline a general structure of a lipid. All lipids do however contain at least one hydrocarbon chain i. Hydrocarbon chains are insoluble in water.
The vast majority of lipids have long hydrocarbon chains which is why they are hydrophobic molecules i.
Lipids Function | Structure, Simple Lipids, Compound Lipids | [email protected]
Fatty acids Fatty acids are a defining feature of lipids. A fatty acid is a long hydrocarbon alkyl chain with an acidic head. A fatty acid can be saturated or unsaturated. If there is no double bonds along the alkyl chain, the fatty acid is saturated.
This is because all of the carbon atoms have bonded to as many hydrogen atoms as possible. The alkyl chain is therefore saturated in hydrogen.
- How does the structure of lipids relate to its function?
The presence of a double bond makes a fatty acid unsaturated because it is possible for the alkyl chain to be bonded to more hydrogen atoms. Fats and Oils Fats are a common and well-known form of lipids.
They are made by bonding fatty acids to an alcohol. The most common fat is a triacylglycerol. Glycerol is a three carbon alcohol and each of the carbons bond to one fatty acid. The structure of the fatty acids of a fat determine if a fat is saturated or unsaturated. Double bonds in one or more alkyl chains of the fatty acids create an unsaturated fat.
2.8: Structure and Function - Lipids and Membranes
A fat molecule with no double bonds in any of its alkyl chains is known as a saturated fat. A double bond creates a bend in an alkyl chain. This reduces how tightly fat molecules can be packed together. Loosely packed fats have lower melting points which is why unsaturated fats, such as vegetable oils, are commonly liquid at room temperature.
Saturated fats on the other hand have higher melting points and are more likely to be found as solids at room temperature. The main function of a fat is to store energy. They are most common in animals because they contain a very large amount of energy for their weight. For mobile animals carrying extra weight is not ideal so storing energy in lightweight molecules is beneficial.
Phospholipids Phospholipids are less well-known than fats and oils but are essential to life on Earth. They are the molecules used to build the membranes found around and inside cells.
Without a plasma membrane a cell would not be able to survive. A phospholipid is similar in structure to a triacylglycerol. It contains TWO fatty acids plus a phosphate group bonded to the three carbons of a glycerol molecule.
The sole difference between a phospholipid and a fat is the replacement of one fatty acid with a phosphate group. A phosphate group has a negative charge so many other molecules can attach themselves to the phosphate group.
This makes a large variety of different possible phospholipids. The combination of fatty acids and a phosphate group make phospholipids ideal for making cellular membranes.
The phosphate group is soluble in water and is therefore attracted to water hydrophilic. The fatty acids are insoluble in water and are hydrophobic. A phospholipid membrane contains two layers of phospholipids.
In both layers the hydrophobic fatty acids point inwards towards each other. Like the other large biological molecules, they play essential roles in the biology of humans and other organisms. Also, many recent dietary studies see sugar as causing a lot more health problems than fat! Fats are just one type of lipid, a category of molecules united by their inability to mix well with water.
Lipids tend to be hydrophobic, nonpolar, and made up mostly of hydrocarbon chains, though there are some variations on this, which we'll explore below.
The different varieties of lipids have different structures, and correspondingly diverse roles in organisms. For instance, lipids store energy, provide insulation, make up cell membranes, form water-repellent layers on leaves, and provide building blocks for hormones like testosterone. Fats and oils A fat molecule consists of two kinds of parts: Glycerol is a small organic molecule with three hydroxyl OH groups, while a fatty acid consists of a long hydrocarbon chain attached to a carboxyl group.
A typical fatty acid contains 12—18 carbons, though some may have as few as 4 or as many as To make a fat molecule, the hydroxyl groups on the glycerol backbone react with the carboxyl groups of fatty acids in a dehydration synthesis reaction. Triglycerides may contain three identical fatty acid tails, or three different fatty acid tails with different lengths or patterns of double bonds.
Synthesis of a tryacylglycerol molecule from a glycerol backbone and three fatty acid chains, with the release of three molecules of water.
Image modified from OpenStax Biology.
Lipid - Wikipedia
Fat molecules are also called triacylglycerols, or, in bloodwork done by your doctor, triglycerides. While many fatty acids are found in fat molecules, some are also free in the body, and they are considered a type of lipid in their own right.
Saturated and unsaturated fatty acids As shown in the example above, the three fatty acid tails of a triglyceride need not be identical to each other. Fatty acid chains may differ in length, as well as in their degree of unsaturation. If there are only single bonds between neighboring carbons in the hydrocarbon chain, a fatty acid is said to be saturated. The thing that fatty acids are saturated with is hydrogen; in a saturated fat, as many hydrogen atoms as possible are attached to the carbon skeleton.
When the hydrocarbon chain has a double bond, the fatty acid is said to be unsaturated, as it now has fewer hydrogens. The double bonds in unsaturated fatty acids, like other types of double bonds, can exist in either a cis or a trans configuration. In the cis configuration, the two hydrogens associated with the bond are on the same side, while in a trans configuration, they are on opposite sides see below. A cis double bond generates a kink or bend in the fatty acid, a feature that has important consequences for the behavior of fats.
Saturated fatty acid example: Unsaturated fatty acid examples: Saturated fatty acids tails are straight, so fat molecules with fully saturated tails can pack tightly against one another. This tight packing results in fats that are solid at room temperature have a relatively high melting point. In contrast, cis-unsaturated fatty acid tails are bent due to the cis double bond. This makes it hard for fat molecules with one or more cis-unsaturated fatty acid tails to pack tightly. So, fats with unsaturated tails tend to be liquid at room temperature have a relatively low melting point — they are what we commonly call oils.
For instance, olive oil is mostly made up of unsaturated fats 2 2. Trans fats are rare in nature, but are readily produced in an industrial procedure called partial hydrogenation. In this process, hydrogen gas is passed through oils made mostly of cis-unsaturated fatsconverting some — but not all — of the double bonds to single bonds.
Trans-unsaturated fatty acids can pack more tightly and are more likely to be solid at room temperature. Partial hydrogenation and trans fats might seem like a good way to get a butter-like substance at oil-like prices. Unfortunately, trans fats have turned out to have very negative effects on human health. Because of a strong link between trans fats and coronary heart disease, the U.