Now, if the chain of carbon atoms has a hydrogen attached to every available space, the result is a saturated fatty acid. Saturated fats tend to be solid at room temperature. Butter, lard, cream cheese. T ake away a couple of the hydrogen atoms from the fatty acid, and create a double bond between two of the carbon atoms. And you now have a monounsaturated fat.
Olive oil is an example of a fat that contains monounsaturated fatty acids.
Monunsaturated fats are liquid at room temperature, but will partially harden when refrigerated. A fatty acid with more than one double bond is referred to as a polyunsaturated fatty acid. Polyunsaturated oils are highly reactive. They can easily interact with oxygen and go rancid. These oils should always be stored in the refrigerator to minimize oxidation.