Which types of fatty acids are considered unsaturated?

Unsaturated fatty acids are characterized by the presence of one or more double bonds in their chemical structure. This unique configuration results in different physical properties compared to saturated fatty acids, which have no double bonds and are typically solid at room temperature.

Monounsaturated fatty acids contain one double bond, making them more fluid than saturated fats. Examples include oleic acid, found in olive oil and avocados. Polyunsaturated fatty acids, on the other hand, contain multiple double bonds, which further enhances their fluidity. Common sources of polyunsaturated fats include fatty fish, walnuts, and flaxseeds.

The first choice, which includes saturated and trans fats, consists of types that are largely considered unhealthy due to their association with increased heart disease risk. The third choice erroneously categorizes fatty acids into complex and simple, which are not types of fatty acids at all but rather refer to types of carbohydrates. The fourth choice indicates that none of the options are correct, which does not align with the fact that monounsaturated and polyunsaturated fatty acids are indeed unsaturated fats.

This clear distinction in structures and properties solidifies that monounsaturated and polyunsaturated fatty acids are the standard classifications of unsaturated fatty acids, making this the correct answer