Question

Which one of the following statements is true regarding digestion and absorption of food on humans?

• A. Fructose and amino acids are absorbed through intestinal mucosa with the help of carrier ions like ${Na}^{+}$
• B. Chylomicrons are small lipoprotein particles that are transported from intestine into blood capillaries
• C. About 60% of starch in hydrolysed by salivary amylase in our mouth
• D. Oxyntic cells in our stomach secrete the proenzyme pepsinogen

Answer 1

The correct option is A Fructose and amino acids are absorbed through intestinal mucosa with the help of carrier ions like ${Na}^{+}$

• Digestion is the process where complex material in the food is broken down to simple nutrients and molecules so that they can be absorbed and circulated in the body.
• The digestion of the food starts in the buccal cavity of the organism where the enzyme amylase is secreted. This enzyme is used for the digestion of the starch present in the food. Though much of the starch is digested in the mouth it is divided in disaccharide units of carbohydrates which will be further digested in intestine.
• The food from the buccal cavity is taken to the stomach via oesophagus where the food is stored for about 3 to 4 hours and mixed with the hydrochloric acid which is secreted by the oxyntic cell present in the mucosa wall of the stomach. This will give the food a acidic pH which is necessary for the activation of the pepsin enzyme which are there for digestion of proteins to peptides.
• This acidic chyme of the stomach is to be transported for further digestion in the intestine where it is mixed with the alkaline secretion released from the liver and pancreas.
• In intestine the food components such as carbohydrates, proteins, lipids etc are digested to small absorbable molecules.
• The carbohydrates are digested to monosaccharides glucose, fructose, galactose, proteins are broken down to amino acids and lipids are reduced to small fat globules called microns.
• Some of these components are already present in the cell fo the body surrounding the digestive track. So for the transport of molecules ion transporters are used sach as sodium ion transporter, etc.
• Glucose is easily digested compared to other molecules of monosaccharides as it is easily soluble in water. Monosaccharides such as fructose and amino acid units are transported to the blood stream along with the sodium ions that are transportedby the sodium ion transporter.
• Fat globules are transported by the lacteal cells that are present in the intestine mucosa of the intestine. Chylomicrons are also used to transport fat to liver and adipose tissue where it can be stored.
• Therfore for the following question option A and C are correct.