Question

Differentiate between Saturated and Unsaturated fatty acids.

Answer 1

Hint: The term ‘saturated’ is used when the maximum number of hydrogen atoms bonded to each carbon atom in a molecule of fat, whereas, the term ‘unsaturated’ is used when in a fat molecule the carbon atoms do not have the maximum number of hydrogen atoms bound to carbon atoms.

Complete Answer:
We can differentiate between saturated and unsaturated fatty acids on the basis of different features as described below:

Sl.No	Saturated fatty acids	Unsaturated fatty acids
1.	These are the simplest form of fats. These are unbranched linear chains of CH2 groups joined together by carbon-carbon single bonds and have a terminal carboxylic acid. They do not have a carbon-carbon double bond.	These are complex fatty acids with bent hydrocarbon chains joined together by carbon-carbon double bonds and have a carboxylic acid group at terminal position. They have one or more carbon-carbon double bonds.
2.	In this type of fatty acids the hydrocarbon chains are linear and unbranched.	In this type of fatty acids the hydrocarbon chains are bent and branched.
3.	In saturated fatty acids the process of hydrogenation is not possible because all the carbon atoms in the hydrocarbon chain are already saturated with the maximum possible number of hydrogen atoms.	In unsaturated fatty acids the process of hydrogenation is possible because the double bonds can be converted to single bonds in addition to hydrogen atoms.
4.	These are mostly found in fats obtained from animal sources. For example - meat, whole milk and butter.	These are mostly found in fats obtained from plant sources. For example - vegetable oil, sunflower oil, mustard oil, avocado oil, etc.
5.	Saturated fatty acids have higher melting point and that is why at room temperature they exist in the solid-state.	Unsaturated fatty acids have lower melting point and that is why at room temperature they exist in the liquid state.
6.	Saturated fatty acids have low chances of oxidation and they have low rancidity.	Unsaturated fatty acids have high chances of oxidation and rancidity.
7.	They have a higher shelf life, so they can be stored for longer duration without decomposition.	They have a lesser shelf life, so they cannot be stored for long duration.
8.	Examples of commonly known saturated fatty acids are – stearic acid, capric acid, lauric acid, palmitic acid, myristic acids, etc.	Examples of unsaturated fatty acids are – linoleic acid, linolenic acid, crotonic acid and oleic acid etc.

Note: Rancidity of fats or oils is the process of their oxidation or hydrolysis when they are exposed to air, moisture or light or bacterial infection. This results in an unpleasant taste and odour.