![]() ![]() Indicate examples of common poisons that block respiration or oxidative phosphorylation and identify their site of action.Įxplain, with examples, how uncouplers may act as poisons by dissociating oxidation via the respiratory chain from oxidative phosphorylation, but may also have a physiological role in generating body heat.Įxplain the role of exchange transporters present in the inner mitochondrial membrane in allowing ions and metabolites to pass through while preserving electrochemical and osmotic equilibrium.Įlectrons flow through the respiratory chain through a redox span of 1.1 V from NAD +/NADH to O 2/2H 2O (see Table 12–1), passing through three large protein complexes: NADH-Q oxidoreductase (Complex I), where electrons are transferred from NADH to coenzyme Q (Q) (also called ubiquinone) ( Figure 13–6) Q-cytochrome c oxidoreductase (Complex III), which passes the electrons on to cytochrome c and cytochrome c oxidase (Complex IV), which completes the chain, passing the electrons to O 2 and causing it to be reduced to H 2O ( Figure 13–3). Identify the five conditions controlling the rate of respiration in mitochondria and understand that oxidation of reducing equivalents via the respiratory chain and oxidative phosphorylation are tightly coupled in most circumstances, so that one cannot proceed unless the other is functioning. ![]() Understand how electron transport through the respiratory chain generates a proton gradient across the inner mitochondrial membrane, leading to the buildup of a proton motive force that generates ATP by the process of oxidative phosphorylation.ĭescribe the structure of the ATP synthase enzyme and explain how it works as a rotary motor to produce ATP from ADP and Pi. Indicate how electrons are passed from reduced coenzyme Q to cytochrome c via Complex III in the Q cycle.Įxplain the process by which reduced cytochrome c is oxidized and oxygen is reduced to water via Complex IV. Understand how coenzyme Q accepts electrons from NADH via Complex I and from FADH 2 via Complex II. After studying this chapter, you should be able to:ĭescribe the double membrane structure of mitochondria and indicate the location of various enzymes.Īppreciate that energy from the oxidation of fuel substrates (fats, carbohydrates, amino acids) is almost all liberated in mitochondria as reducing equivalents, which are passed by a process termed electron transport through a series of redox carriers or complexes embedded in the inner mitochondrial membrane known as the respiratory chain until they are finally reacted with oxygen to form water.ĭescribe the four protein complexes involved in the transfer of electrons through the respiratory chain and explain the roles of flavoproteins, iron sulfur proteins, and coenzyme Q.
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