Lipids

Fats and oils, which may be saturated or unsaturated, can be unhealthy but also serve important functions for plants and animals.

Waxes are nonpolar lipids that plants and animals use for protection and have many functions in society.

Phospholipids are amphipathic molecules that make up the bilayer of the plasma membrane and keep the membrane fluid.

Steroids, like cholesterol, play roles in reproduction, absorption, metabolism regulation, and brain activity.