Biochemistry

Under aerobic conditions, the conversion of lactate formed from glucose during glycolysis proceeds in two directions: about 1/5 of lactate is oxidized to CO2 and H2O, the rest is converted to glycogen. The first stage of aerobic decomposition of lactate is its oxidation to pyruvate involving lactatedehydrogenase. However, the vast majority of animal and plant cells are normally under aerobic conditions, and pyruvate, which is formed during the breakdown of glucose, is not restored to lactate, but is gradually oxidized to CO 2 , and H 2 O in the aerobic stage of catabolism. In this case, the oxidative decarboxylation of pyruvate initially occurs with the formation of acetyl-CoA. Oxidative decarboxylation proceeds on mitochondria. It is catalyzed by complex multi-enzyme and polycoenzyme systems, which consist of several enzymes (dehydrogenase itself, etc.) and several coenzymes, including thiaminepyrophosphate (TPP), thiaminediphosphate (TDP), lipoic acid (LA), NAD, HSCoA, FAD, Mg 2 * (Fig. 11.5). Each component of the enzyme system is involved in the implementation of the relevant process link. Reactions occur in several stages. Figurell.5 - The transformation of the Pyruvic acid 227