What is the biological importance of derived lipids?

Derived lipids are biologically important as they are used in other reactions to form substances including sterols and bile juices. Cholesterol is one important derived lipid for example, as all steroids are synthesized from it. It also can be oxidized in the liver to form 7-dehydrocholesterol, which later is converted into vitamin D3 from UV rays. Cholesterol also functions to regulate the fluidity of cell membranes.