Biochemistry

Inside the cells, the metabolism is regulated by the level and orientation of the transformations of energy sources. So, if it is not enough, then acetyl-CoA passes from the cytoplasm to the mitochondria, where it is oxidized with the energy release. With an excess of energy, acetyl-CoA is used for the synthesis of fatty acids, cholesterol, acetone bodies (Fig. 13.2). Steroid hormones Figure 13.2 - Acetyl-CoA metabolism Vitamin D Regulation can be carried out at the stage of transformation of individual molecules, i.e., at the molecular level. Thus, processes of decomposition and synthesis of glucose, glycerol, higher fatty acids, amino acids and other molecules are realized. The molecular level is controlled by the combined activity of enzymes, substrates, the presence of activators and inhibitors, optimal conditions for the activity of enzymes, etc. Thus, the metabolism and energy in the body is regulated at different levels and is provided by a wide variety of factors. However, control over the entire regulatory activity of the body is carried out by the neurohumoral system. The close connection of nervous and humoral systems is evidenced by the fact that a decrease in the activity of one of them is offset by an increase in the activity of the other. The regulatory influence of the nervous system is manifested to a large extent through humoral factors, which include hormones, mediators, metabolites, and others. The nervous system plays a dominant role in regulation, since it is characterized by a more accurate reaction to the action of various stimuli and can cause the necessary functional changes. Humoral factors act more slowly than nerve signals, but longer. 277