Any living organism is an open, dynamic system in which various processes are constantly carried out. During the course of life, cells accumulate nutrients, form new organoids, grow, divide, and perform their specific functions, while actively synthesizing organic substances – plastic metabolism and spending energy stored in the process of energy metabolism. Especially active assimilation occurs during the period of growth of the body. But for the implementation of biosynthesis processes, the presence of one energy is not enough. We also need material from which the body can synthesize its organic compounds. The most important element necessary for all living organisms is carbon.
For example, the characteristics of metabolism in bacteria are that:
– its intensity has a sufficiently high level, which is possibly due to a much larger ratio of surface to unit mass than multicellular ones;
– processes of dissimilation prevail over processes of assimilation;
– the substrate spectrum of substances consumed by bacteria is very wide – from carbon dioxide, nitrogen, nitrites, nitrates to organic compounds, including anthropogenic substances – environmental pollutants (thereby ensuring self-cleaning processes);
– bacteria have a very wide range of different enzymes – this also contributes to the high intensity of metabolic processes and the breadth of the substrate spectrum.
Localization of bacteria enzymes is divided into 2 groups:
– exoenzymes – bacterial enzymes secreted into the environment and acting on the substrate outside the cell (for example, proteases, polysaccharides, oligosaccharidases);
– endoenzymes – bacterial enzymes that act on the substrates inside the cell (for example, enzymes that break down amino acids, monosugar, synthetase).
The synthesis of enzymes is genetically determined, but the regulation of their synthesis is due to direct and feedback, i.e. for some it is repressed, and for others it is induced by a substrate. Enzymes whose synthesis depends on the presence of the appropriate substrate in the medium (for example, beta-galactosidase, beta-lactamase) are called inducible.
Another group of enzymes, the synthesis of which does not depend on the presence of a substrate in the medium, is called constitutive (for example, glycolysis enzymes). Their synthesis always takes place, and they are always contained in microbial cells in certain concentrations.
They study the metabolism of bacteria using physico-chemical and biochemical research methods during the cultivation of bacteria under certain conditions on special nutrient media containing a particular compound as a substrate for transformation. This approach allows us to judge the metabolism by a more detailed study of the processes of various types of metabolism (proteins, carbohydrates) in microorganisms. Based on these features, bacteria are widely used.