Question

(a) Draw a labelled diagram of human alimentary canal.
(b) Explain the digestion of fat in our body. Where does this process take place?
(c) What is the role of saliva in the digestion of food?

Answer 1

b) The digestion of fats in the intestine is aided by emulsification. Emulsification is the process of the breaking up of fat globules into much smaller emulsion droplets. This process is performed by the bile salts. Emulsification greatly increases the surface area where water-soluble lipase enzyme breaks lipids into fatty acids and monoglycerides. Bile salt combines with phospholipids in chyme and emulsified the hydrophobic end with lipid and hydrophilic end with water, and break down the insoluble lipid globule into the simple form by enzymatic activity.

c) Salivary glands are present in oral cavity that secrete saliva which is released into mouth. Saliva contains bicarbonate and salivary amylase and serves to initiate the process of starch digestion into simple sugars by breaking the αα-1, 4- glycosidic linkage of glucose.