LIPIDS

     Fat is one ester group of organic compounds found in many plants, animals, or humans and is very useful for human life fats are liquid at room temperature are called oils, fats while the term is usually used for the solid form. Generally derived from animal fats, while oil from plants. Some examples of fats and oils is beef fat, coconut oil, corn oil, and fish oil.

     A. Structure and Nomenclature Formula Fat
Fats are esters of glycerol with carboxylic acids of high interest. Constituent fatty acids are called fatty acids.  In fat, one glycerol molecule binds three molecules of fatty acids, therefore fat is a triglyceride. The general structure of fat molecules as shown in the illustration below:

In the fat structure above formula, R1-COOH,-COOH R2, and R3-COOH are fatty acid molecules attached to the glycerol.

Common names of fat is triglycerides. Naming fat starting with glyceryl followed by the name of fatty acids. example :

The fatty acids found in nature are palmitic acid (C15H31COOH), stearic acid (C17H35COOH), oleic acid (C17H33COOH), and linoleic acid (C17H29COOH).

• Palmitic acid, also called heksadekanoik acid, is the major saturated fatty acids in meat and dairy products. Palmitic acid is the main component of the oil palm trees (palm oil and coconut oil). Retinyl palmitate is an antioxidant and a good source of vitamin A added to low-fat milk.
• Stearic acid is a saturated fatty acid most commonly found in nature following the palmitic acid. Stearic acid is mainly used in the production of detergents, soaps, and cosmetics such as shampoo and shaving cream produk.Asam stearate are used to produce dietary supplements.
  
  In fireworks, stearic acid is often used to coat metal powders such as aluminum and iron. This prevents oxidation, so the composition of which will be stored for long periods of time.
  
  Stearic acid is a common lubricant for injection molding and pressing of ceramic powders. It is also used as a mold release for foam latex baked in a stone mold
• Oleic acid is a fatty acid that is found in almost
  all foodstuffs, both animals and plants. Oleic acid from animal
  are found in the bone and fat in milk. Oleic acid plant
  are found in the pulp and seeds.
  
  function of oleic acid in the body:
  - As a source of energy
  -Is an antioxidant that works to inhibit cancer
  -Lowers cholesterol
  -As the solvent medium vitamin A,
• Linoleic acid (LA) is a polyunsaturated fatty acid used in the biosynthesis of arachidonic acid (AA) and thus some prostaglandins. It is found in the cell membrane lipids. It is abundant in many vegetable oils, comprising more than half (by weight) of poppy seeds, safflower, sunflower and corn oils.
  
  Linoleic acid is a member of a group of essential fatty acids called omega-6 fatty acids are essential for the dietary needs of all mammals. Another group of essential fatty acids are omega-3 fatty acids, such as Alpha-linolenic acid. Omega-6 deficiency symptoms include dry hair, hair loss, and poor wound healing.

. Types of Fatty Acids

Fat molecules formed from glycerol and three fatty acids. Therefore, the classification based on the types of fat over their constituent fatty acids. Based on the type of bond, the fatty acids are grouped into two, namely:

a. Saturated fatty acids
     Saturated fatty acids, the fatty acids are all carbon atoms bond to form a single bond carbon chain (saturated). Example: lauric acid, palmitic acid, and stearic acid.

b. Unsaturated fatty acids
     Unsaturated fatty acids, the fatty acids containing double bonds in the carbon chain.
Example: oleic acid, linoleic acid and linolenic acid.


Physical properties of fats

a. At room temperature, the animal fat in general is a solid, while the plants in the form of fat from liquid.

b. The fat has a high melting point of saturated fatty acids, whereas fat has a low melting point of unsaturated fatty acids. Example: Tristearin (esters of glycerol with three molecules of stearic acid) has a melting point of 71 ° C, whereas triolein (esters of glycerol with three molecules of oleic acid) has a melting point of -17 ° C.

c. Fats containing short-chain fatty acids dissolved in water, while fat contains long-chain fatty acids are not soluble in water.

d. All the fat soluble in chloroform and benzene. Alcohol heat is a good fat solvent


Use of Fats and Oils in Everyday Life
Fat or oil can be used for multiple purposes, including the following.

1. Energy source for the body
Fat foods or serve as a backup energy source. Fats are energy-rich foods. Combustion of 1 gram of fat produces about 9 kilocalories.

2. Materials for butter or margarine
Fat or oil can be turned into butter or margarine by hydrogenation.

3. Ingredients soap making
Soap can be made from a reaction between fats or oils with KOH or NaOH. Soap containing Na metal called hard soaps (reacting strongly to the skin) and is often called soap. While soap containing K metal called soft soap and in everyday life known as bath soap.