Lingual lipase

Definition

Lingual lipase is an enzyme secreted by the salivary glands in the mouth that begins the process of lipid digestion by breaking down triglycerides into diglycerides and free fatty acids. This enzyme plays a crucial role in the digestion of dietary fats, especially in infants who rely on milk fat for nutrition before the full digestive function of the pancreas develops.

5 Must Know Facts For Your Next Test

1. Lingual lipase is particularly active in infants, as it helps digest milk fats before pancreatic enzymes are fully functional.
2. The action of lingual lipase is initiated in the mouth and continues in the stomach, where it can function in an acidic environment.
3. Lingual lipase is less significant in adults compared to pancreatic lipase but still plays a role in overall fat digestion.
4. This enzyme is part of the first step of lipid digestion, preparing fats for further breakdown by other lipases in the digestive system.
5. Lingual lipase can account for a small portion of total lipid digestion, highlighting its role as an initiator rather than the primary enzyme responsible for fat digestion.

Review Questions

• How does lingual lipase contribute to lipid digestion compared to pancreatic lipase?
  • Lingual lipase initiates lipid digestion in the mouth by breaking down triglycerides into diglycerides and free fatty acids, primarily functioning in infants who rely on milk fat. In contrast, pancreatic lipase takes over this process in the small intestine, where it further breaks down these products into monoglycerides and free fatty acids. While lingual lipase starts the digestion process, pancreatic lipase is responsible for completing it and maximizing fat absorption.
• Discuss the importance of lingual lipase during infancy and its role in fat metabolism.
  • During infancy, lingual lipase plays a vital role as it allows babies to effectively digest breast milk or formula, which contains high levels of fats. Since infants have limited pancreatic function, this enzyme ensures that dietary fats are broken down early on for better absorption and energy utilization. Its activity highlights how critical it is for babies to obtain sufficient energy from fats for growth and development during their early stages of life.
• Evaluate how lingual lipase's function might differ under various physiological conditions such as pH changes or hormonal influences during digestion.
  • Lingual lipase operates optimally at a low pH, which is present in the stomach after food intake. If there are changes in pH, such as increased acidity or alkalinity, its activity may be affected. Hormonal influences from digestive hormones like gastrin or secretin can also impact enzyme secretion from salivary glands. Understanding these physiological changes is crucial since they can alter the efficiency of lipid digestion initiated by lingual lipase and affect overall nutrient absorption.

Related terms

Triglycerides: The main form of fat found in the body and in foods, consisting of three fatty acids attached to a glycerol molecule.

Pancreatic lipase: An enzyme produced by the pancreas that continues the digestion of fats in the small intestine, breaking down triglycerides into monoglycerides and free fatty acids.

Bile salts: Detergent-like molecules produced by the liver that emulsify fats, increasing their surface area for enzyme action during digestion.