Nutrition Digestion and Absorption

Digestion helps in the breakdown of food into small portions that can be absorbed and used by the body. The food taken by the body is often in large proportions that cannot be taken by the body. According to Brown (2016), the process of digestion begins in the mouth and ends in the small intestines. The digestion of the carbohydrates takes place through the gastrointestinal tract. In the mouth, the carbohydrates are broken down into small pieces and mixed with the saliva. The saliva in the mouth moistens the food and breaks down some polysaccharides. The crushing of food by the teeth and the mixing of the saliva moisturizes it for easy swallowing. Due to the short time food takes place in the mouth, only a small portion of the digestion takes place in the mouth.

When food reaches the stomach, it mixes with the acids and digestive enzymes that continued to break down the starch. The food takes some time in the stomach due to the effects of dietary fibers and this helps to provide the feeling of fullness and satiety. Most of the carbohydrate digestion takes place in the small intestine. The small intestines harbor the pancreatic amylase that provides a further breakdown to the polysaccharides and the maltose. The outer membrane of the small intestines has special enzymes that provides the final breakdown of the disaccharides.  At the end of the small intestines, all the polysaccharides shall have been broken down (Seymour, 2005). The intestinal cells are responsible for absorbing the produced monosaccharaides into the body. Eventually, the monosaccharaides are converted to glucose to release the energy required by the body cells. Since the different carbohydrates are digested at different stages, the process of carbohydrate digestion depends on the type of carbohydrate consumed.

When food reaches the large intestines, all the sugars and the starches shall have been digested. The component of food that reaches the large intestines is mostly the dietary fibre. In the large intestines, the bacterial enzymes digest the dietary fiber into fatty acids and gas. This food attracts water that helps to soften it before it is released through the anus. However, not all the dietary fiber is released through the anus as some are fermented by the bacteria to release some energy (Seymour, 2005). Most of the carbohydrate absorption takes place in the small intestines. However, some small portion of glucose is absorbed through the linings of the mouth. During blood circulation, the liver cells take up fructose and galactose and convert them to glucose that is needed by the body cells.

Therefore, the carbohydrate digestive system can be explained in terms of the waste disposal system. The mouth acts as the waste collection by collection centre and it is here that the waste disposal system begins. In the collection centre, the waste is mixed with water and crashed. Here, some important materials such as are collected. The waste is then passed through the conveyor to the next point. Here, the waste is mixed with some compounds and other finer elements are removed. The waste is then taken to the third stage where the rough elements are removed. From here, the final product is unusable and is disposed as unwanted materials.



Brown, J.E. (2016). Nutrition Now 8th Edition. Cengage Learning

Seymour, S. (2005). Guts: Our Digestive System. HarperCollins


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