Digestion

All animals are heterotrophs and require a variety of “raw materials” and energy sources (carbohydrates, fats, proteins, vitamins, water and minerals) for the synthesis of numerous compounds that make up their cells. The structural components of the molecules of proteins, fats and carbohydrates are most often connected by anhydride bonds, which are formed by the removal of a water molecule or some equivalent reaction. These bonds are broken by hydrolytic cleavage with the addition of a water molecule.

For the hydrolytic cleavage of bonds of various types, various enzymes are required, the action of which is highly specific. The same or very similar groups of enzymes are involved in the digestion process in different organisms, but the place of their formation, action and regulation are different.

Digestion can be intracellular, when food particles are captured by the cell and digested within it. Or extracellular - cells secrete enzymes into the intestinal cavity, where hydrolysis occurs. Digestive products are low molecular weight substances that can be absorbed by cells.

Higher animals have special organs for digestion. Digestive products are transported through the circulatory system to the cells that use them.

The human digestive tract is a long tube of separate organs that receive, digest and absorb food. Administration includes chewing and swallowing. Absorption is possible after the molecules are digested by enzymes.

The wall of the digestive tract is equipped with a semi-permeable membrane that allows only small molecules of hydrolysis products to pass through.

The human digestive system is responsible for the process of digesting food and provides the body with the energy necessary for life. The digestive tract includes the mouth, esophagus, stomach, small intestine and large intestine. The process of digestion begins in the oral cavity, where mechanical processing of food occurs - chewing,