University:
Liberty University
Course:
BIOM 500 | Introduction to Biomedical Sciences
Academic year:

2024
Views:

91

Pages:

5
Author:

Sheha A.

Digestion of Fat 1. Digestion in Stomach Lipid digestion begins in the stomach Gastric lipase hydrolyzes triglycerides to diglycerides and free fatty acids Peristaltic contraction of the stomach mixes the food with gastric juices Only 30% of fat can be digested in the stomach because the enzymes are less active at low pH of stomach contents 2. Digestion in the Intestine Pancreatic lipase is the major enzyme that digests triglycerides in the intestine Bile acids emulsify fats, increasing the surface area for digestion Chyme is released from the stomach to the intestine, stimulating the release of the pancreatic and biliary secretions In the intestine, the pH is alkaline, which is optimal for pancreatic lipase activity As this moves it changes the pH of the intestine. For the action of pancreatic lipase, the pH is increased. Bile also contains bile salts which facilitate the emulsification of fats in the intestine. This enzyme hydrolyzes the ester linkages in the triglycerides, releasing fatty acids and monoglycerides. Pancreatic lipase breaks the ester linkage i.e. C-1 & C-3 of triglycerides. At C-3, first bond breaks and then C-1. Pancreatic lipase first converts 1,2-diacylglycerol to 2-monoglyceride and a fatty acid molecule is released. At each step, one ester bond is broken. From C-1 to C-2, 2-monoglyceride is then converted to 1-monoglyceride and a fatty acid molecule is released. This final step is very slow.