Question

1. Compare the functions of the small intestine and the large intestine.
2. Why do proteins need to incorporate into the triglyceride molecules to form the chylomicrons?
3. Why can’t the chylomicrons move directly into the capillaries like monosaccharides and amino acids?

Answer 1

Comparison of Small Intestines and Large Intestines

1. The small intestine is a part of the digestive system that lies between the stomach and large intestine whereas the large intestine is the terminal part of the intestine.

2. The small intestine is longer and narrower whereas the large intestine is wider and shorter than the small intestine

3. The small intestine has three components- duodenum, jejunum and ileum whereas the large intestine has these components-Colon, cecum, rectum and anal canal.

4. The small intetsine exhibits small movements whereas the large intestine shows very less mobility

5. It is responsible for the absorption of nutrients from the digested food whereas the large intestine takes part in the absorption of electrolytes and water.

6. The small intestine does not play a role in vitamin synthesis whereas large intestine has a role in the production of vitamins.

7. The longitudinal muscles of small intetsine are arranged in circular layers whereas the longitudinal muscles are arranged in three bands known as Teniae Colie.

8. The small intestine are composed of villi whereas the large intestine does not possess villi.

9. The small intestine possesses enzymes and is involved in digestion whereas the large intestine does not possess digestive enzymes and is not responsible for the digestion of food.

answer to second question:

Chylomicrons represent the transport form of dietary lipids from the intestines to other locations in the body where they are needed. Since triglycerides are insoluble in plasma and cannot be carried as such, they are transported with the help of proteins and hence are packaged as lipoprotein particles. Chylomicrons are composed of a main central lipid core that consists primarily of triglycerides and the protein specific to chylomicrons is ApoB48.

answer to third question:

Transport of lipids into the capillaries  is different from monosaccharides and amino acids. Instead of being absorbed directly into capillary blood, chylomicrons are transported first into the lymphatic vessel that penetrates into each villus called the central lacteal from where it drains into the lymphatic system and then into blood. The reason that chylomicrons do not directly enter the capillaries is that they are too big to pass through the capillary pores.