This creates a final proton pump, pumping 2 protons from the matrix through cytochrome complex IV, directly into the intermembrane space of the mitochondrion. Complex IV is the last step in the ETC, and the electrons that have been driving these reactions now need another place to go.
To solve this problem, an oxygen atom, which has a very strong attraction for electrons, picks up two electrons from complex IV, along with two some free protons from the mitochondrial matrix, to simply form water H In essence, the FINAL acceptor of the electrons at complex IV is oxygen which forms water with the protons and electrons it accepts into its structure.
The many protons that this process pumps in the intermembrane space create an imbalance in hydrogen ion concentration charge that the cell does not like. An unexpected error occurred. Previous Video 8. This range of ATP is approximate for three reasons. Second, NADH produced in glycolysis cannot pass through the mitochondrial membrane and therefore must pass its high-energy electrons to other electron carriers within the mitochondria, and, depending on the cell type, produce FADH2 or NADH, yielding either 1.
Third, the energy produced by respiration is also used to power other activities, like the transport of pyruvate through the mitochondrial membrane, yielding about 30 or 32 ATPs.
Cellular respiration produces ATP molecules per glucose molecule. Although most of the ATP results from oxidative phosphorylation and the electron transport chain ETC , 4 ATP are gained beforehand 2 from glycolysis and 2 from the citric acid cycle. The ETC is embedded in the inner mitochondrial membrane and comprises four main protein complexes and an ATP synthase.
This distribution of protons generates a concentration gradient across the membrane. Four protons are needed to synthesize 1 ATP. Since a single NADH produces 2. Importantly, glycolysis occurs in the cytosol and the ETC is located in the mitochondria in eukaryotes. The mitochondrial membrane is not permeable to NADH, hence the electrons of the 2 NADH that are produced by glycolysis need to be shuttled into the mitochondria.
Given the different ATP yield depending on the electron carrier, the total yield of cellular respiration is 30 to 32 ATP per glucose molecule. Da Poian, A. Nature Education 3 9 Lane, N. To learn more about our GDPR policies click here. If you want more info regarding data storage, please contact gdpr jove. Your access has now expired. Provide feedback to your librarian. If you have any questions, please do not hesitate to reach out to our customer success team.
Rotenone : inhibits complex I, rat poison and insecticide. Cyanide : inhibits terminal electron transfer to oxygen, Complex IV. Carbon Monoxide : inhibits cytochrome oxidase by competing with an oxygen- binding site, Complex IV.
The proton gradient also creates a charge difference across the inner mitochon. Dinitrophenol DNP , causes ATP formation to cease but oxygen consumption remains rapid in an attempt by the mitochondria to maintain the proton gradient. Sign up using Facebook. Sign up using Email and Password.
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