5 Answers
Bile 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 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.
Bile juice plays two important roles, i.e. of changing the medium of food from acidic to alkaline and of emulsifying the fat. Alkaline medium is necessary for action of enzymes in the succus entericus. Thus, bile is important for digestion.
Bile helps in breaking down of fats into very small micelles which is known as emulsification. It also activates lipases which act on emulsified fats and digest them. Bile also helps in stimulation, peristaltic movement, acts as a buffer and helps in lubrication of food.
Liver does not secrete digestive enzymes. It contains bile pigments hilirubin and hiliverdin which are the break down products of haemoglobin of dead RBCs. bile salts, cholesterol and phospholipids. Bile helps in emulsification of fats. Bile salts reduce the surface tension of fat droplets and break them into small globules. Bile also activates lipase to digest lipids.
Bile emulsifies the fat making it easier digest by enzymes. Bile juice also helps inactivation of lipase, the enzyme which digests fat. Additionally, bile converts the acidic chyme to alkaline so that other enzymes can work on food.