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The hydrophobic behavior of lipids is based on their molecular structure.The main biological functions of lipids include energy storage, acting as structural components of cell membranes, and participating as important signaling molecules.<br />
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What are fats? Fats are a group of compounds that are soluble in organic solvents and insoluble in water. Compounds made of glycerol and fatty acids are called fats. Fats may be either solid or liquid at room temperature, depending on what they are made of, and how they are architected.<br />
The molecule H2O (water) has a unique shape; the two hydrogen atoms forming a "V" shape, rather than a straight line. The electrons spend more time orbiting the oxygen nucleus than orbiting the two hydrogen nuclei, leaving the oxygen more negatively charged and the hydrogen more positively charged. Therefore, the entire molecule is "Polar"; that is with one end slightly positive and one end slightly negative.<br />
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Fats are hydrophobic or insoluble in water because the non-polar, covalent bonds linking carbon and hydrogen in the lipid structure aren't attracted to the polar bonds of water. <br />
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We've all heard the terms 'unsaturated fat' and saturated fat'. What is the difference between a saturated fat than an unsaturated fat? Essentially, there are two broad categories of fat: saturated fat and unsaturated fat. These two types of fat differ in their chemical structure. Saturated fatty acids (the building blocks of saturated fat) have no double bonds (a particular kind of chemical link between adjoining molecules) and this lack of double bonds means that there are no gaps in the fatty acid chain: it is packed with CH2 molecules. Unsaturated fatty acids (the building blocks of unsaturated fat), on the other hand, have double bonds and these double bonds break up the string of CH2´s and create gaps within the fatty acid chain. We will explore how this difference in chemical structure affects how different types of fat interact with the body below.<br />
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Saturated fats (meats, butter, dairy products) are solid at room temperature, whereas unsaturated fats (vegetable oils) are liquid at room temperature. Due to their difference in chemical structure, saturated fats and unsaturated fats exert different effects within the body. Because saturated fatty acid chains have no gaps, they are able to pack together very tightly. When these tightly packed saturated fatty acids enter the bloodstream, they increase levels of "bad" cholesterol known as low-density lipoprotein (LDL) cholesterol and clog arteries. In comparison, unsaturated fats do not increase "bad" cholesterol and, in fact, are able to increase levels of "good" cholesterol known as high-density lipoprotein (HDL) cholesterol. HDL is able to grab LDL and escort it to the liver where it is broken down and eventually removed from the body. Thus, by increasing levels of HDL, unsaturated fats are able to protect against the damage done by saturated fats.<br />
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But what is Hydrogenation? Does it help or hurt?<br />
Hydrogenation is the chemical reaction that results in addition of hydrogen (H2). The process is usually employed to reduce or saturate organic compounds. The process typically constitutes the addition of pairs of hydrogen atoms to a molecule. Catalysts are required for the reaction to be usable; non-catalytic hydrogenation takes place only at very high temperatures. Hydrogen adds to double and triple bonds in hydrocarbons<br />
Hydrogenation is a high tech process. Vegetable seeds are cleaned and bleached to remove all color, taste, smells and impurities. The liquid vegetable oil is then heated to high temperatures and a catalyst (commonly nickel, but could be palladium, platinum or rhodium) is added. Hydrogen is bubbled through the liquid. The mixture is then filtered to remove the metal, leaving hydrogenated vegetable oil. Water, whey, salt, vitamins, colorings, flavorings and emulsifiers may then be added to produce hydrogenated margarine.<br />
The advantage of all this is that it gives a uniform product that is solid at room temperature and has a long shelf life. This last characteristic is very important both for manufacturers and consumers. It gives manufacturers increased flexibility, and it means that consumers can buy products and not have to worry so much about 'best before' dates.<br />
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There is a potential problem with hydrogenation. The hydrogenation process changes the nature of some of the fats into a form that is not easily recognized by the body (trans fatty acids). We do not know the long term effect of our constant exposure to these fats, although evidence is beginning to appear linking them to many degenerative diseases.<br />
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Here's a disease caused by fatty deposits...Atherosclerosis is a hardening of the arteries, caused by deposits of fat along the inner walls of arteries.<br />
Fatty deposits cause the immune system to induce local inflammation. This then leads to narrowing and eventually, blockage, of the impacted artery. This blockage interrupts the regular flow of blood, which, depending on which artery is impacted, can lead to serious medical problems like heart attacks or strokes.<br />
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But what about the benefits of fats? This category of molecules is important for many forms of life, serving both structural and metabolic functions. Fats play a vital role in maintaining healthy skin and hair They insulate body organs against shock, maintaining body temperature, They promote healthy cell function. They also serve as energy stores for the body. Fats are broken down in the body to release glycerol and free fatty acids. The glycerol can be converted to glucose by the liver and thus used as a source of energy. Fat also serves as a useful buffer towards a host of diseases. When a particular substance, whether chemical or biotic—reaches unsafe levels in the bloodstream, the body can effectively dilute—or at least maintain equilibrium of—the offending substances by storing it in new fat tissue. This helps to protect vital organs, until such time as the offending substances can be metabolized and/or removed from the body.<br />
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In conclusion, fats have an importantant role to play in the maintenance of a healthy life.</p>
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