Lecture 91. List the three basic steps in respiration a. Oxidation of the initial electron donor and NADH productionb. Membrane-associated electron transport chain reoxidizes NADH to NAD+ and creates a proton motive force. This step ends with the reduction of the terminal electron acceptorc. ATP synthase drives ATP production2. Compare and contrast the general features of fermentation and respiration a. Production of fermentation products is not needed to reoxidize NADH, glucose (or another electron donor) can be oxidized all the way to CO2 and produce more NADH.3. Recall the two main functions of the CAC a. Biosynthesis of amino acidsb. Energy production4. Recall the overall reactions of glycolysis and the CAC a. Glycolysis:i. Glucose -> 2 pyruvate + 2 ATP + 2 NADHb. Citric Acid Cycle:i. Pyruvate -> 3 CO2 + GTP + 4 NADH + FADH (Multiple by 2)5. Recall the two main functions of the electron transport chain a. Two types: carriers of e- and H+, and carriers of e- onlyb. Transfer electrons by interacting with proteins or enzymes6. Explain how the electron transport chain pumps protons out of the cytoplasm a. organic substrate donates electrons to initial oxioreductase (ex. Flavine)b. Electron transferred to carrier (ex. Quinone)c. Carried electon (inside the Quinone) transferred to terminal oxidase (ex. Heme) Electrons travel from most negative potentialto most positive potential7. Compare and contrast the different electron carriers in the electron transport chain a. Carriers of 2 electrons and 2 H+ : i. Flavines(covalently attached to proteins) and Quinones (diffuse through memebranes)b. Carriers of electons only:i. Iron-sulfur clusters(always bound to proteins) and Hemes(in Heme containing proteins) Prosthetic groups= covalently attached to proteins8. Compare and contrast the number of protons pumped out of the cell from the oxidations of NADH and FADH2 a. For every NADH oxidized 8H+ extrudedb. For every FADH2 oxidized 4H+ extruded9. Explain how the ATPase gets its energy to synthesize ATP a. Protons pass through F0, force c subunits to rotate in the mb, transmit the torque to the cytoplasmic part of the complex. Because the F1 part is attched to F00 through b2 proteins, the head cannot turn, force a conformational change in subunits beta: accumulation of potential energy. Release of this energy and conformational change make it possible to produce ATP.10. Calculate the energetic efficiency of a given respiratory process a. DGo’ = ΣGof (products) - ΣGof (reactants) b. 100 x 2 [energy in ATP generated/energy available]11. Predict which respiratory process will yield more energy for cell growth a.
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