Question

Neha consumed boiled sweet potatoes and boiled eggs for breakfast. Help her to understand some steps in the process of digestion of the food taken by her by answering the questions given below.

1. Which of these food items is rich in proteins? In which part of the alimentary canal is the digestion of this component initiated? Name the enzymes, conditions required and the glands associated with the digestion here.
   OR
2. Which of these food items contains fats? How is it digested?
3. Which of these food items is rich in starch? How is its digestion initiated?
4. The figure given below represents parts of the human alimentary canal. Which of these parts will have the maximum amount of digested food as soon as the process of digestion is completed?

   Human alimentary canal

Answer 1

1. Eggs are rich in proteins. The digestion of proteins is initiated in the stomach. Gastric glands present in the wall of the stomach release hydrochloric acid, a protein digesting enzyme called pepsin and mucus. The hydrochloric acid creates an acidic medium which facilitates the action of the enzyme pepsin.
   OR
2. Eggs contain fats. Bile juice from the liver breaks down large fat globules into smaller ones for increasing the efficiency of the enzymes and making the medium alkaline. Emulsified fats are digested by lipase secreted by the pancreas.
3. Sweet potatoes are rich in starch. The saliva secreted by salivary glands present in the buccal cavity contains an enzyme called salivary amylase that breaks down starch, which is a complex molecule, to give sugar.
4. The small intestine will have a maximum amount of digested food, as the process of digestion is completed in the small intestine.