electron transport chain and oxidative phosphorylation pdf

Electron transport chain and oxidative phosphorylation pdf

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Oxidative phosphorylation

Satisfying The Body's Need for Energy

Electron Transport Chain

electron transport chain lecture notes pdf

Oxidative phosphorylation

In eukaryotes , this takes place inside mitochondria. Almost all aerobic organisms carry out oxidative phosphorylation. This pathway is so pervasive because it releases more energy than alternative fermentation processes such as anaerobic glycolysis. The energy stored in the chemical bonds of glucose , ultimately derived from food, is released by the cell in the citric acid cycle producing carbon dioxide, and the energetic electron donors NADH and FADH. Oxidative phosphorylation uses these molecules to produce ATP , which is used throughout the cell when ever energy is needed. During oxidative phosphorylation, electrons are transferred from the electron donors to a series of electron acceptors in a series of redox reactions ending in oxygen as the last acceptor. In eukaryotes , these redox reactions are catalyzed by a series of protein complexes within the inner membrane of the cell's mitochondria, whereas, in prokaryotes , these proteins are located in the cell's outer membrane.

Endocrine Disrupters and Metabolism View all 22 Articles. There is increasing evidence supporting the characterization of the pesticide DDT and its metabolite, DDE, as obesogens and metabolic disruptors. Elucidating the mechanism is critical to understanding whether the association of DDT and DDE with obesity and diabetes is in fact causal. One area of research investigating the etiology of metabolic diseases is mitochondrial toxicity. Several studies have found associations between mitochondrial defects and insulin resistance, cellular respiration, substrate utilization, and energy expenditure. Although the mitotoxicity of DDT and DDE was established 20—40 years ago, it was not viewed in the light of the diseases faced today; therefore, it is prudent to reexamine the mitotoxicity literature for mechanistic support of DDT and DDE as causal contributors to obesity and diabetes, as well as associated diseases, such as cancer and Alzheimer's disease.

Satisfying The Body's Need for Energy

Mitochondria pp Cite as. Oxidative phosphorylation is the single most important function of mitochondria. As the term implies, it is the process whereby the energy released from the oxidation reactions of the electron transfer chain is used for the synthesis of ATP. Because of its central role in aerobic metabolism, biochemists have invested substantial time and effort in studies of the mechanism of oxidative phosphorylation. Although numerous solutions to this problem have been proposed, they usually had to be abandoned in light of later evidence—the regularity with which this has happened has caused the remark to be made that no worse fate could befall anyone working on oxidative phosphorylation than to solve it.

Electron Transport Chain

Electron Transport — the oxidation phase of Oxidative Phosphorylation 3. As charges move, the work that is done can be used to make ATP. In biologic systems, the cells use electron transport chain to transfer electrons stepwise from substrates to oxygen. These series of complexes transmit electrons from electron donors to electron acceptors by way of redox reactions where in reduction and oxidation takes place simultaneously. Electron transport chain comprises of the following: Complex I: NADH dehydrogenase; Complex II: succinate dehydrogenase Electron transport is the most complex and productive pathway of cellular respiration.

In eukaryotic cells, the vast majority of ATP synthesis occurs in the mitochondria in a process called oxidative phosphorylation. Even plants, which generate ATP by photophosphorylation in chloroplasts, contain mitochondria for the synthesis of ATP through oxidative phosphorylation. Oxidative phosphorylation is linked to a process known as electron transport Figure 5.

electron transport chain lecture notes pdf

The components have progressively more positive E 0 values leading to electron transfer and energy production for pumping protons out of the matrix. The components span the inner membrane asymmetrically to facilitate proton pumping. Components : b cytochromes, Fe-S-protein center, cytochrome c 1.

Every day, we build bones, move muscles, eat food, think, and perform many other activities with our bodies. All of these activities are based upon chemical reactions. However, most of these reactions are not spontaneous i. Hence, the body needs some sort of "free-energy currency," Figure 1 a molecule that can store and release free energy when it is needed to power a given biochemical reaction. Just as purchasing transactions do not occur without monetary currency, reactions in the body do not occur without energy currency.

Oxidative Phosphorylation

3 comments

  • Gretalmoli1966 01.06.2021 at 20:24

    The electron transport chain is the last component of aerobic respiration and is the only part of glucose metabolism that uses atmospheric oxygen.

    Reply
  • Cosette A. 02.06.2021 at 02:57

    Due to the existence of electron leak and proton leak, not all electrons in the ETC can be transferred to the final electron acceptor O 2 and the energy released by the transferred electrons cannot be completely coupled with ATP generation.

    Reply
  • Swebo 04.06.2021 at 12:47

    You have just read about two pathways in cellular respiration—glycolysis and the citric acid cycle—that generate ATP.

    Reply

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