fatty+acids

__Fatty Acids__ A fatty acid is a carboxylic acid with a long aliphatic chain. It is a long-chain hydrocarbon with an even amount of carbon atoms, plus a carboxylic acid end group. When fatty acids are metabolized, the produce large amounts of ATP, which makes it a very important energy source to the body. Fatty acids can be found in many oils and fats such as olive oil, lard, butter, and more.



Types of fatty acids
Three dimensional representations of several fatty acids Fatty acids that have double bonds are known as unsaturated. Fatty acids without double bonds are known as saturated. They differ in length as well.

Length of free fatty acid chains
Fatty acid chains differ by length, often categorized as short, medium, or long.
 * Short-chain fatty acids (SCFA) are fatty acids with aliphatic tails of fewer than six carbons (i.e. butyric acid ).
 * Medium-chain fatty acid (MCFA) are fatty acids with aliphatic tails of 6–12 carbons, which can form medium-chain triglycerides.
 * Long-chain fatty acid (LCFA) are fatty acids with aliphatic tails longer than 12 carbons.
 * Very long chain fatty acid (VLCFA) are fatty acids with aliphatic tails longer than 22 carbons

Unsaturated fatty acids
Comparison of the //trans// isomer (top) Elaidic acid and the//cis//-isomer oleic acid. Unsaturated fatty acids have one or more double bonds between carbon atoms. (Pairs of carbon atoms connected by double bonds can be saturated by adding hydrogen atoms to them, converting the double bonds to single bonds. Therefore, the double bonds are called unsaturated.) The two carbon atoms in the chain that are bound next to either side of the double bond can occur in a [|//cis// or //trans//] configuration. //cis//A //cis// configuration means that adjacent hydrogen atoms 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 and restricts the conformational freedom of the fatty acid. The more double bonds the chain has in the //cis// configuration, the less flexibility it has. When a chain has many //cis// bonds, it becomes quite curved in its most accessible conformations. For example, oleic acid, with one double bond, has a "kink" in it, whereas linoleic acid , with two double bonds, has a more pronounced bend. Alpha-linolenic acid, with three double bonds, favors a hooked shape. The effect of this is that, in restricted environments, such as when fatty acids are part of a phospholipid in a lipid bilayer, or triglycerides in lipid droplets, cis bonds limit the ability of fatty acids to be closely packed, and therefore could affect the melting temperature of the membrane or of the fat.//trans//A //trans// configuration, by contrast, means that the next two hydrogen atoms are bound to //opposite// sides of the double bond. As a result, they do not cause the chain to bend much, and their shape is similar to straight saturated fatty acids. In most naturally occurring unsaturated fatty acids, each double bond has three //n// carbon atoms after it, for some n, and all are cis bonds. Most fatty acids in the //trans// configuration ( trans fats ) are not found in nature and are the result of human processing (e.g., hydrogenation ). The differences in geometry between the various types of unsaturated fatty acids, as well as between saturated and unsaturated fatty acids, play an important role in biological processes, and in the construction of biological structures (such as cell membranes). They can also make a large difference concerning diet. Since saturated fats can pack closely together they can lead to build up of cholesterol in arteries. By replacing saturated fats with unsaturated ones, you can lower your chance of high cholesterol and heart attack. Common foods that contain unsaturated fats includes oils, nuts, avocados, fish, and peanut butter.

Saturated fatty acids
Saturated fatty acids are long-chain carboxylic acids that usually have between 12 and 24 carbon atoms and have no double bonds. Thus, saturated fatty acids are saturated with hydrogen (since double bonds reduce the number of hydrogens on each carbon). Because saturated fatty acids have only single bonds, each carbon atom within the chain has 2 hydrogen atoms (except for the omega carbon at the end that has 3 hydrogens). Health-wise, saturated fats are not very good for you. Since the chains are rigid they are able to pack together tightly, causing issues in the cardiovascular system. Common foods that contain saturated fats include cheese, butter, red meat, and some vegetable and nut products such as chocolate and coconut oil.
 * ~ Chemical structure ||~ //C//://D// ||
 * Caprylic acid || CH3(CH2)6COOH || 8:0 ||
 * Capric acid || CH3(CH2)8COOH || 10:0 ||
 * Lauric acid || CH3(CH2)10COOH || 12:0 ||
 * Myristic acid || CH3(CH2)12COOH || 14:0 ||
 * Palmitic acid || CH3(CH2)14COOH || 16:0 ||
 * Stearic acid || CH3(CH2)16COOH || 18:0 ||
 * Arachidic acid || CH3(CH2)18COOH || 20:0 ||
 * Behenic acid || CH3(CH2)20COOH || 22:0 ||
 * Lignoceric acid || CH3(CH2)22COOH || 24:0 ||
 * Cerotic acid || CH3(CH2)24COOH || 26:0 ||