Biochemistry

CHAPTER 3. ENZYMES 3.1 GENERAL CONCEPT ON ENZYMES At the base of all the vital processes of the body are thousands of chemical reactions that are catalyzed by special proteins - enzymes. The name "enzyme" comes from the Latin word "fermentum" (sourdough); the second term is "enzyme" - from the Greek en - inside, zyme - yeast. It is with the processes of fermentation that the doctrine of enzymes begins. Due to enzymes in living organisms, such amazing transformations occur that, under other conditions, are not always possible even when using the most modem achievements of science and technology. So, for example, it would take 300 years to break down hydrogen peroxide molecules into molecular oxygen and water in the presence of iron, while the catalase enzyme carries out this process in a living cell per 1 second. Enzymes cause the acceleration of vital processes. However, this does not violate the universal laws of nature, since only those processes that are thermodynamically possible but proceed slowly are accelerated. The direction of chemical processes is ensured by the ordered distribution of enzymes in the cell, some of which are “ tied ” to certain structures, others are contained in the cytoplasm and migrate to different parts of the cell, subject to regulatory influences. Therefore, many different reactions occur in cells at the same time in various, including opposite, directions. This fact served as an occasion for the outstanding Hungarian scientist A.Saint-Gyorgy to say: “ Biology is the science of the unbelievable. ” A great contribution to fermentology was made by domestic scientists A.Ya.Danilevsky, I.P.Pavlov, A.N.Bach. So, I.P.Pavlov in his experiments showed that digestive enzymes are proteins, since the activity, digesting ability, of gastric juice changes in parallel with the change in the amount of protein. The idea of the protein nature of all enzymes has been confirmed in a huge number of studies. It is interesting to note that although I.P.Pavlov worked mainly with digestive enzymes, he attached more general importance to these catalysts in the life processes. In the first lecture on the physiology of digestion, the scientist writes: “ All chemical processes in the body are directed precisely by these substances (ie, enzymes); they are the causative agents of all chemical transformations". Nutrition science is based on an accurate knowledge of the phased breakdown of nutrients under the influence of digestive system enzymes, the quantitative and qualitative composition of which is significantly influenced by the nature of the incoming nutrients. Many hereditary human diseases are 78