We might say that what the body does with food is “digest” it. But what exactly does this mean? Our digestive system has two basic jobs to do with the food we take in. The first job is to break down large food molecules so that they can be carried through the body. It is impossible for large molecules to pass through the walls of the cells and tissues. Starch must be broken down to sugar, oil to soaps, and protein to amino acids before they can pass through the cell walls.
The second job of the digestive system is to transform the “foreign” molecules of food into human molecules. Don’t forget that we take in food molecules of all kinds: milk, meat, coffee, potato, fish, and so on.
While we can swallow a piece of chicken, we cannot replace any part of the body with chicken protein. The human body is made up of molecules of human protein, and they are usually arranged in a special kind of way. So the body must break down the molecules of butter, flour, fish, fruits, and so on, into their elements. Then human proteins, fats, and starches must be built up from them.
The process of digestion is quite complicated. It begins in the mouth with the saliva, which helps break down starches. It then continues in the stomach, where most of the process of digestion takes place. Here, juices from the stomach wall are mixed with the food.
The food, now in liquid form, then goes into the small intestine. The breakdown of proteins is completed here; fats are split into their finer parts, and starch digestion is a15o completed here. As the digested material passes over the surface of the small intestine, it is absorbed into the blood and lymph. In this way, nourishment reaches all the cells of the body.
What Are The 7 Nutrients In Food?
There are seven main classes of nutrients that the body needs. These are carbohydrates, proteins, fats, vitamins, minerals, fiber, and water.