Final answer:
Bile is the substance made by the liver that breaks up fat particles. It emulsifies fats in the small intestine, making them easier to digest.
Step-by-step explanation:
The substance made by the liver that breaks up fat particles is bile. Bile is a mixture secreted by the liver and stored in the gallbladder before being released into the small intestine. Its primary function is to emulsify fats, breaking them down into smaller globules that can be easily digested in the watery environment of the small intestine.