Bile juice is a digestive juice secreted by the liver. Although it does not contain any digestive enzymes, it plays an important role in the digestion of fats. Bile juice has bile salts such as bilirubin and biliverdin. These break down large fat globules into smaller globules in the small intestine so that the pancreatic enzymes can easily act on them. This process is known as emulsification of fats. Bile juice also makes the medium alkaline and activates lipase.
Functions of saliva are:
1) Lubrication and binding of food: It helps in lubrication of food as well as the mouth parts and esophagus for the smooth movement of food.
2) Solubilises the dry food material
3) It keeps the mouth clean
4) Starch digestion: Saliva contains amylases which digest starch. So, starch digestion begins in mouth itself.
5) Provides alkaline environment in mouth.
Pancreatic juice:- The pancreas secretes pancreatic juice which contains enzymes like trypsin for digesting proteins and lipase for breaking down emulsified fats.