Question

Why is it necessary for the food to be broken down and digested?

• A. Large molecules in intact food pass through the digestive epithelium and enter the cell through the membrane, damaging the nuclear membrane. Hence, it must be broken down.
• B. Fats present in intact food contain very large molecules that cannot pass through cell membranes. Fats need to be passed through the digestive epithelium to be utilised.
• C. Large molecules present in intact food cannot pass through cell membranes. Nutrients need to be separated from food to be passed through the digestive epithelium to be utilised.
  
• D. If not broken down, large molecules produce toxic substances that pass through the epithelium of the digestive tract and are utilised by the cells. This can be lethal to the cells.

Answer 1

The correct option is C Large molecules present in intact food cannot pass through cell membranes. Nutrients need to be separated from food to be passed through the digestive epithelium to be utilised.


Food that we consume contains complex organic molecules like carbohydrates, proteins and fats that cannot pass through the cell membranes of the small intestine where absorption takes place. In order to be absorbed by the body, these large and complex molecules have to be broken down into simple nutrients like glucose, amino acids, fatty acids and glycerols respectively.