Information AboutFatty Acid |
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| fatty acids | |
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Industrially, fatty acids are produced by the Hydrolysis of the Ester linkages in a Fat or biological oil (both of which are Triglyceride s), with the removal of Glycerol . See Oleochemical s. Reduction of fatty acids yields Fatty Alcohol s. TYPES OF FATTY ACIDS Saturated fatty acids Saturated fatty acids do not contain any Double Bond s or other Functional Group s along the chain. The term "saturated" refers to Hydrogen , in that all carbons (apart from the Carboxylic Acid {Link without Title} group) contain as many hydrogens as possible. In other words, the omega (ω) end contains 3 Hydrogen s (CH3-) and each carbon within the chain contains 2 hydrogens (-CH2-). Saturated fatty acids form straight chains and, as a result, can be packed together very tightly, allowing living organisms to store chemical energy very densly. The fatty tissues of animals contain large amounts of long-chain saturated fatty acids. In IUPAC Nomenclature , fatty acids have an -oic Acid suffix. In Common Nomenclature , the suffix is usually -ic. Some saturated fatty acids are:
Unsaturated fatty acids Unsaturated fatty acids are of similar form, except that one or more Alkene Functional Group s exist along the chain, with each alkene substituting a singly- Bond ed " -CH2-CH2-" part of the chain with a Doubly-bonded "-CH=CH-" portion (that is, a carbon double bonded to another carbon). The two next carbon atoms in the chain that are bound to either side of the double bond can occur in a '' Cis '' or '' Trans '' configuration. ; ''cis'' : A ''cis'' configuration means that the two carbons are on the same side of the double bond. The rigidity of the double bond freezes its conformation and, in the case of the ''cis'' isomer, causes the chain to bend. The more double bonds the chain has in the ''cis'' configuration, the more bent it is. When a chain has many ''cis'' bonds, it becomes quite curved. For example, Oleic Acid , with one double bond, has a "kink" in it, while Linoleic Acid , with two double bonds, has a more pronounced bend. Alpha-linolenic Acid , with three double bonds, forms a hooked shape. ; ''trans'' : A ''trans'' configuration, by contrast, means that the next two carbon atoms are bound to ''opposite'' sides of the double bond. As a result, they don't cause the chain to bend much, and their shape is similar to the straight saturated fatty acids. In most naturally occurring unsaturated fatty acids, each double bond has 3''n'' carbon atoms after it, for some n, and all are Cis bonds. Most fatty acids in the ''trans'' configuration (trans fats) are unnatural and the result of human processing. The differences in geometry between these various types of unsaturated fatty acids, as well as between saturated and unsaturated fatty acids, plays an important role is biological processes, and in the construction of biological structures (such as cell membranes). Nomenclature There are two different ways to make clear where the double bonds are located in molecules. For example:
Example of unsaturated fatty acids:
Alpha-linolenic, docosahexaenoic, and eicosapentaenoic acids are examples of Omega-3 Fatty Acid s. Linoleic acid and arachidonic acid are Omega-6 Fatty Acid s. Oleic and erucic acid are Omega-9 Fatty Acid s. Stearic and Oleic acid are both 18 C fatty acids. They differ only in that stearic acid is saturated with hydrogen, while oleic acid is an unsaturated fatty acid with two fewer hydrogens. Essential fatty acids See Also: Essential fatty acid The human body can produce all but two of the fatty acids it needs. These two, Linoleic Acid and Linolenic Acid , are widely distributed in plant and fish oils.Since they are not made in the body and must be taken from food, they are called essential fatty acids. In the body, essential fatty acids are used to produce hormone-like substances that regulate a wide range of functions, including blood pressure, blood clotting, blood lipid levels, the immune response and the inflammation response to injury infection Essential fatty acids are the polyunsaturated fatty acids, Linoleic Acid and Alpha-linolenic Acid , which are the parent compounds of the Omega-6 and Omega-3 fatty acid series, respectively. They are essential in the human diet since they cannot be synthesized by the body. Humans can easily make saturated fatty acids or monounsaturated fatty acids with a double bond at the omega-9 position, but do not have the enzymes necessary to introduce a double bond at the omega-3 or omega-6 position. As a result, these fatty acids must be obtained from food sources; hence, they are "essential." The essential fatty acids are very important to the human immune system and to help regulate blood pressure, since they are used to make compounds such as Prostaglandin s. The brain is also highly enriched in derivatives of linolenic and alpha-linoleic acids. Changes in the levels and balance of these fatty acids caused with a typical Western diet of processed food and high intensity agriculture has been associated with depression and behavioral change, including violence. Change to a more natural diet or consumption of supplements to compensate for dietary imbalance is associated with a reduction in violent behavior, and increases attention span. This finding has been replicated in studies within schools as well as a double blind study in a prison.12 Trans fatty acids See Also: Trans fat A trans fatty acid (commonly shortened to '''trans fat''') is an unsaturated fatty acid molecule that contains a '' Trans '' Double Bond between Carbon atoms, which makes the molecule less kinked compared to fatty acids with '' Cis '' double bonds. Research suggests a correlation between diets high in ''trans'' fats and diseases like Atherosclerosis and Coronary Heart Disease . FREE FATTY ACIDS Fatty acids can be bound or attached to other molecules, like Triglyceride s or Phospholipid s. When they are not attached to other molecules, they are known as "free" fatty acids. The uncombined fatty acids or '''free fatty acids''' may come from the breakdown of a triglyceride into its components (fatty acids and glycerol). Free fatty acids are an important source of fuel for many tissues since they can yield relatively large quantities of ATP . Many cell types can use either Glucose or fatty acids for this purpose. However, heart and skeletal muscle prefer fatty acids. On the other hand, the brain cannot use fatty acids as a source of fuel, relying instead on glucose, or on Ketone Bodies produced by the liver from Fatty Acid Metabolism during starvation, or periods of low carbohydrate intake. PH of a solution. The significance of their pKa values therefore only has relevance to the types of reaction that they take part in. Even those fatty acids that are insoluble in water will dissolve in warm Ethanol , and can be Titrated with Sodium Hydroxide solution using Phenolphthalein as an indicator to a pale pink endpoint. This analysis is used to determine the free fatty acid content of fats, i.e. the proportion of the Triglyceride s that have been Hydrolyzed . REACTION OF FATTY ACIDS Fatty acids react just like any other carboxylic acid, which means they can undergo Esterification , Hydrolysis , and acid-base reactions. Unsaturated fatty acids can additionally undergo addition reactions, most commonly Hydrogenation , which is used to convert vegatable oils into margarine. With partial hydrogenation, unsaturated fatty acids can be isomerized from ''cis'' to ''trans'' configuration. Autoxidation and rancidity See Also: Rancidification Fatty acids at room temperature undergo a chemical change known as Autoxidation . The fatty acid breaks down into Hydrocarbon s, Ketone s, Aldehyde s, and smaller amounts of Epoxide s and Alcohol s. Heavy metals present at low levels in fats and oils promote autoxidation. Fats and oils often are treated with Chelating Agents such as Citric Acid . SOURCES SEE ALSO EXTERNAL LINKS |
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