What primary substance does the liver produce to assist in the breakdown of fats?

The primary substance produced by the liver to assist in the breakdown of fats is lipase. Lipases are enzymes specifically designed to catalyze the hydrolysis of fats (lipids) into fatty acids and glycerol, facilitating the digestion and absorption of dietary fats in the digestive system. These enzymes play a crucial role in fat metabolism.

While cholesterol is a product of liver function and contributes to various bodily processes, including the formation of cell membranes and hormones, it does not directly assist in fat breakdown. Glucose is primarily a carbohydrate and serves as a major source of energy, while urea is a waste product formed from the metabolism of proteins and is involved in the excretion of nitrogen from the body. None of these substances play a direct role in the enzymatic process of fat breakdown as lipases do.