Oxidation occurs in the tissues and cells noncellular substance. It consists of:
1) hydrogen or recoil dehydrogenation 2) joining the O2 and 3) transfer claim background or changes valency. Oxidation begins with dehydration, t. E. With the fact that dehydrogenase enzymes activated hydrogen, a part of the oxidizing agents. Then, the oxidation of hydrogen to form water, with the participation of enzymes oxidases which are iron respiratory enzymes.
Respiratory enzymes are strongly associated with the cells – the catalysts of tissue respiration, which is the main source of energy. They differ from oxidases that with their participation O2 perceives only the active hydrogen tissues, while involving oxidases, hydrogen can be perceived and molecular O2. Furthermore dehydrogenases and oxidases involved in oxidative processes, and other enzymes, eg peroxidase affecting the formation of compounds of type peroxides. These enzymes are activated O2, promote the oxidation of hard oxidizable substances in normal conditions.
Physical and chemical bases of oxidative processes in cells – electron transfer enzymes (cytochromes). In cellular respiration very important role played by the cytochrome system (cytochrome oxidase cytochrome +). Cytochromes and flavoproteins – hydrogen carriers. In cellular respiration are also participating carriers amino groups, phosphate and other enzymes. Many enzymes involved in. cellular respiration are derivatives of vitamins (B1, B2, etc.). Furthermore, in redox processes in cells involved vitamin C.
Thus, the extremely complex process of cellular respiration is carried out by enzymes and vitamins. The intensity of cell respiration in people decreases with age.
Terms and recoil absorption of oxygen and carbon dioxide in the blood and lung tissues
O2 uptake in blood flowing in the pulmonary capillaries, is facilitated by the fact that the lungs is removed from the blood CO2.
Flow to the capillaries of the lungs venous blood contains a significant amount of carbon dioxide, which lowers the affinity of hemoglobin for O2. However, when the venous blood into the alveoli gives CO2, O2 affinity of Hb increases, which promotes blood O2 saturation and conversion of venous blood to arterial. In tissue capillaries, on the contrary, the blood is saturated with carbon dioxide, which lowers the affinity of hemoglobin for O2 and O2 promotes kickback tissues.
O2 uptake hemoglobin also affects the concentration of hydrogen ions in blood. The greater the concentration of hydrogen ions, the lower affinity of hemoglobin for O2. The concentration of hydrogen ions depends mainly on the content of carbon dioxide. The lower the pressure of carbon dioxide in the blood, the greater the amount of O2 can bind hemoglobin. The highest concentration of hydrogen ions in the tissues, the smallest – in the alveoli.
Finally, the effect of oxyhemoglobin dissociation temperature. An increase in temperature accelerates the only dissociation of oxyhemoglobin, but almost no effect on the rate of binding of O2 by hemoglobin. In tissues with the increased activity of the body temperature of the blood increases slightly, which increases the impact of O2 in blood. Transferring O2 hemoglobin several times higher under physiological conditions (when its content in the erythrocytes, at body temperature, pH and salt composition of 7.35 body) than in pure hemoglobin solution.