Question

Select the correct match of the digested products in humans given in column l with their absorption site and mechanism in column ll.

List l	List ll
Glucose	1. Duodenum, move as chylomicrons
Fructose	2. Small intestine, facilitated diffusion
Glycerol, fatty acids	3. Large intestine, active absorption
Cholesterol, maltose	4. Glucose transporter.

A. A-4, B-2, C-1, D-3
B. A-2, B-4, C-1, D-3
C. A-2, B-4, C-3, D-1
D. A-2, B-3, C-4, D-1

Answer 1

Digestion is the metabolic process wherein the food breakdowns into smaller and smaller portions until they can be absorbed and incorporated in the body. This is a major function carried out by the human digestive system. The digestive system of humans includes the gastrointestinal tract and other solid organs such as the pancreas, gallbladder, and liver that facilitate the digestion process. The gastrointestinal tract constitutes the mouth, oesophagus, stomach, small intestine, large intestine, and anus.

Complete answer:
The major site of digestion and absorption of nutrients in the small intestine and duodenum is considered to be the most active site of digestion. Absorption of nutrients takes place through different mechanisms which include passive transport, active transport, facilitated transport, and simple diffusion. Food substances are absorbed into the bloodstream by one of these mechanisms.
-Glucose: Glucose is one of the three carbohydrates absorbed into the blood in the small intestine by absorptive cells. They are absorbed across the biological membrane by secondary active transport along with sodium, through the Sodium-Glucose co-transporter.
-Fructose: Fructose is a carbohydrate digested and absorbed in the small intestine through facilitated diffusion. Once the fructose is absorbed into the bloodstream it transports to the liver for processing and metabolism.
-Glycerol, Fatty acids: Glycerol and fatty acids cannot be absorbed into the blood directly. They adhere to small droplets called micelles to form a micelle-component complex which reforms into fat globules coated with proteins called chylomicrons. Through the process of assimilation, these components are absorbed into the blood. The assimilation process involves the transport of chylomicrons to the lymph vessels where the digested products get absorbed into the blood and reach the tissue to carry out activities.
-Cholesterol, maltose: These are absorbed into the bloodstream across the cell membrane from a region of lower concentration to a region of higher concentration with the utilization of energy.

Therefore, the correct option is A. A-4, B-2, C-1, D-3.

Note: Large intestine is known as the largest part of the gastrointestinal tract. Water absorption and waste storage prior to excretion are done here. Defecation is known as the removal of waste from the body.