The characteristics of most unsaturated fatty acids found within a human cell are deprotonated carboxylic acid and cis double bonds.
With the exception of steroids, fatty acids are carboxylic acids that provide the structural foundation of fats, oils, and all other types of lipids. More than 70 have been found in the natural world.
They are typically unbranched, contain an even number of carbon atoms (often 12–20), and can be divided into groups based on the existence and quantity of carbon–carbon double bonds.
As a result, saturated fatty acids don't have any carbon-to-carbon double bonds, while monounsaturated fatty acids have one, and polyunsaturated fatty acids have two or more.
