C.4.1

= = =Composition of Fats and Oils:=

Fats (solid) and oils (liquid) belong to a group of organic compounds called **triesters** or **triglycerides.** They are formed from the condensation reaction of one **glycerol** (**propane-1,2,3-triol**) molecule and three **fatty acid** (long chained carboxylic acid) molecules.


 * Structural Formula of Glycerol**:

The glycerol molecule contains a backbone of three carbon atoms with **three hydroxyl or alcohol groups (-O-H) attached**. Its condensed structural formula is CH2OHCHOHCH2OH.

Fatty acids consist of the hydrocarbon chain (H and C atoms) with a **carboxylic acid group (-COOH)** at one end
 * Fatty Acids**:

When one glycerol molecule and three fatty acid molecules combine in a condensation reaction, one fat molecule (trigyceride) is formed and three molecules of water.


 * Triglyceride**:

The equation below shows how a fat is formed. Notice how the H from the glycerol and the alcohol (-OH) group from the fatty acid are lost to form water. The process of forming a fat is called a **condensation reaction**. The bond formed between the glycerol and fatty acid molecules is called an **ester** or **glycoside link**. The reverse process is called hydrolysis.

General formula of a Fat or an Oil