Fact 1: Lipids may consist of fatty acids alone, or they may contain other molecules as well.

Fact 2: Lipids are the fats that circulate in blood.

Given the two facts above, answer the question "Fatty acids that circulate in the blood may contain other what?" with the following options: 
- organs
 - Acids
 - Energy
 - Energy.
 - molecules
 - hydrocarbons
 - cell walls
 - waters


 

     molecules    