Oxidation and energy generation

See also Standard Reduction Potential, Oxidations and Energy Generation, Electron Transport, Henderson-Hasselbalch Equation (from Chapter 2). 

Figure 12-2. Role of the respiratory chain of mitochondria in the conversion of food energy to ATP. Oxidation of the major foodstuffs leads to the generation of reducing equivalents (2H) that are collected by the respiratory chain for oxidation and coupled generation of ATP.

The roles of NADH and NADPH in the overall strategy of metabolism are shown in Fig. 5.17. Fuel molecules, such as glucose, are oxidised in catabolism they lose electrons and these reducing equivalents are transfered to an environmental acceptor such as oxygen, with concomitant ATP production (see oxidative phosphorylation, Section 5.5.6). However, some reducing equivalents are conserved and re-utilised in the synthesis of cellular components, with the consumption of ATP, as oxidised intermediates are reduced to synthetic precursors with subsequent polymerisation. The pyridine nucleotides thus have roles in both synthetic and energy generation process. 

Mitochondrial dysfunction has long been considered to play a central role in the development of cell injury during ischemia-reperfusion and hypoxia-reoxygenation [19]. Besides the inhibition of fatty acid oxidation, mitochondrial energy generation is diminished because of defects in respiratory chain function. Inhi-hition of the FO-Fl-ATPase leading to impaired function of respiratory complex I has been observed in I/R injury. Similar to ischemia, dsplatin has been shown to affed mitochondrial respiratory complexes and func-... 

In the electrothermic part of the furnace, electrical energy introduced via three carbon electrodes, keeps the bath molten and completes the lead oxide reduction. Fumes generated in the electrothermic section are oxidized in a post-combustion chamber by adding ambient air, before the vapor is cooled, dedusted, and released to the atmosphere. 

ATP Adenosine triphosphate. Chemical energy generated by substrate oxidations is conserved by formation of high-energy compounds such as adenosine diphosphate (ADP) and adenosine triphosphate (ATP) or compounds containing the thioester bond. 

The two processes are electron transport and oxidative phosphorylation. NADH is reoxidised by the process of electron transport using the electron transport chain and the energy released from this process is harnessed by oxidative phosphorylation to generate ATP. We noted earlier that the two processes are intimately linked or coupled. Normally one cannot proceed without the other. 

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