Question

Sucrose is broken down in the lining layer of the intestine to form glucose and fructose. The products are
A. Passed into blood
B. Poured into the intestinal lumen
C. Utilised in the living cells
D. Passed inwardly to supply the whole wall of the intestine.

Answer 1

Hint: Sucrose is the common table sugar. It is a disaccharide. Our body cells cannot use such complex products for energy production; they have to be converted into simpler products. Therefore, the enzyme Sucrase from intestinal lumen cells breaks down sucrose into fructose and glucose. These are monosaccharides, simple products.

Complete answer:
The food products that we consume are complex in nature. They have to be converted into simpler products for utilization by cells. This is done in the gastrointestinal tract with the help of a variety of enzymes present in the luminal cells These enzymes convert the large substances into smaller molecules and the complex structures into simpler products which make it easier for the self to utilise the food for energy production.

Sucrose is one such enzyme that converts the complex disaccharide sucrose into the monosaccharides namely glucose and fructose. These products can be easily utilised by the cells. These monosaccharides produced are not directly utilized by the intestinal lining cells. Instead, they are poured into the intestinal lumen from where they get absorbed into the later parts of the small intestine- the jejunum and ileum to reach the blood and via blood, these products reach different cells of the body and are utilised for energy production. The products will be poured into the intestinal lumen.

Thus the correct answer is option ‘B’.

Note: Just like sucrase, there are a variety of different enzymes present in the gastrointestinal tract for the breakdown of complex dietary structures into simpler products. For example, lactase converts lactose into glucose and galactose. Similarly, there are enzymes for protein and fat metabolism too.