Lipases in the gastrointestinal tract play a critical role in fat digestion. More than 95% of fat in food consists of triglycerides, which are categorized based on the length of fatty acids connected to glyceride backbone. The length of long-chain triglycerides prevent their absorption through the intestinal mucosa. For that reason lipases in the gastrointestinal tract must hydrolyse it to smaller molecules, free fatty acids and monoglyceride, before absorption can occur.