What is a fatty acid ?

A fatty acid is like a chain composed of carbon, hydrogen and oxygen.
The number of carbons on the chain varies from 4 to 24.

A carbon offers 4 electrons
A hydrogen offers 1 electron
An oxygen offers 2 electrons.

These compounds share two electrons to form a bond between them.

When carbons are linked by a single bond we call the fatty acid: saturated (SFA).
When two carbons are linked by a double bond the fatty acid is called: monosaturated (MUFA).
When more than two carbons are linked by a double bond the fatty acid is called: polyunsaturated (PUFA).

The more hydrogen a fatty acid contains, the more saturated it is.

The fatty acid can be divided into two parts:

1. The methyl group and its chain:
CH3-(CH2)p-[CH=CH]-(CH2)q-etc...
This part of the molecule is water insoluble and oil-soluble.

2. The carboxyl group:
-COOH
It is the acid part. This part is water-soluble and does not dissolve in oil.