Fat is broken down by X into Fatty Acids and Y. Identify X and Y.

• A. X = protease, Y = glycerol
• B. X = amylase, Y = glycerol
• C. X = lipase, Y = glycerol
• D. X = lipase, Y = fatty acids

Answer: (C)

Fat digestion relies on a lipase enzyme that acts on triglycerides, the main fats in the diet. Lipase breaks those triglycerides apart to release the glycerol backbone and free fatty acids. In the small intestine, this process yields glycerol plus fatty acids, which are then absorbed. So the enzyme is lipase and the other product is glycerol. The other enzymes listed break other nutrients (proteins or carbohydrates), so they wouldn’t produce fatty acids or glycerol from fat, confirming why lipase with glycerol fits best.