Now, to demonstrate what we mean by fatty acid, let's take a look at the most common type of fatty acid in humans and other animals, known as palmitic acid. Now, let's take a look at this molecule. So this entire section is the hydrocarbon chain, and this functional group is that carboxylic acid. So we have a tiny polar section and this dominant non polar section. So that's why fatty acids are predominantly non polar. Now, this is one of the many fatty acids that we can find in nature.