The inhibitor X prevents coenzyme Q (Q) from participating in electron transfer in the electron transport chain. (a) Will the presence of X prevent electrons from N ADH from passing through the electron trans- port chain? Explain why or why not. (b) Compound Y is a non-physiological reducing agent capable of directly reducing cytochrome c1 in Complex III. Would oxygen consumption resume upon the addition of compound Y to mitochondria inhibited by inhibitor X? Be sure to explain your answer.

The inhibitor X prevents coenzyme Q (Q) from participating in electron transfer in the electron transport chain. (a) Will the presence of X prevent electrons from N ADH from passing through the electron trans- port chain? Explain why or why not. (b) Compound Y is a non-physiological reducing agent capable of directly reducing cytochrome c1 in Complex III. Would oxygen consumption resume upon the addition of compound Y to mitochondria inhibited by inhibitor X? Be sure to explain your answer.

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter20: Electron Transport And Oxidative Phosphorylation

Section: Chapter Questions

Problem 11P

See similar textbooks

Similar questions

Under standard conditions, is the oxidation of ubiquinol (Coenzyme Q) by O2 sufficiently exergonic to drive the synthesis of ATP? If yes, how many ATP can be synthesized assuming 100% efficiency?
A dialyzed pigeon liver extract will catalyze the conversion of acetyl-CoAto palmitate and CoASH if supplied with Mg2+, NADPH, ATP, HCO3-, andcitrate.(a) If H14CO3– is supplied, what compounds will become labeled (permanently or transiently) during the course of the reaction? In whatcompounds will 14C accumulate?(b) Explain the role of citrate in this reaction.
Describe the effects of (1) oligomycin and (2) uncouplers of oxidative phosphorylation, e.g., dinitrophenol (DNP), carbonyl cyanide-p- trifluoromethoxyphenylhydrazone (FCCP), on respiration and ATP synthesis when added to a suspension of mitochondria with excess malate, ADP, and inorganic phosphate (Pi).
Four electron carriers, a, b, c, and d, whose reduced and oxidized formscan be distinguished spectrophotometrically, are required for respirationin a bacterial electron transport system. In the presence of substrates andoxygen, three different inhibitors block respiration, yielding the patterns ofoxidation states shown below. What is the order of the carriers in the chainfrom substrates to O2, and where do the three inhibitors act?O and R indicate fully oxidized and fully reduced, respectively.
It is estimated that each electron pair donated by NADH leads to the synthesis of approximately three ATP molecules, whereas each electron pair donated by FADH2 leads to the synthesis of approximately two ATP molecules. What is the underlying reason for the difference in yield for electrons donated by FADH2 versus NADH?
For the Complex III in the electron transport chain: Complex III step 1: UQH2 is oxidized in a 2 electron process. Cytochrome c is reduced and UQ is reduced to UQH in two 1 electron processes. Complex III step 2: UQH2 is oxidized in a 2 electron process. Cytochrome c is reduced and UQH is reduced to UQH2 in two 1 electron processes. The necessary standard reduction potentials are: UQ + 2H+ + 2e- UQH2 E° = 0.06 V cyt c (Fe3+) + e- cyt c (Fe2+) E° = 0.254 V UQ + H+ + e- UQH. E° = 0.03 V UQH. + H+ + e- UQH2 E° = 0.19 V Calculate the total redox potential of the complex. Now calculate how many moles of protons can be translocated across the inner mitochondrial membrane if translocation of 1 mole requires 23 kJ. Calculate the free energy available for proton translocation assuming a 2electron process for each complex.
If α-ketoglutarate is removed from TCA cycle and used to make glutamate, how many of each of the cofactors (not intermediates) and high energy molecules in the TCA cycle are lost? How much ATP does this equate to (NADH = 2.5 ATP, FADH2 = 1.5 ATP)?
From the complete oxidation of glucose (glucose → 6CO2), how many total NADH electron carriers are produced?
If a reaction has a ΔG°′ value of at least −30.5 kJ · mol−1, suffi -cient to drive the synthesis of ATP (ΔG°′ = 30.5 kJ · mol−1), can it still drive the synthesis of ATP in vivo when its ΔG is only −10 kJ · mol−1? Explain.
How many mol of NADH can be obtained upon the beta oxidation of stearic acid? How many mol of ATP can be obtained upon the complete oxidation of 1 mol stearic acid? How many steps in glycolysis in which ATO is converted to ADP?
Compare the delta ΔG0' values for the oxidation of succinate by NAD+ and by FAD. Use the data given in Table 18.1 to find the E0' of the NAD+-NADH and fumarate-succinate couples, and assume that E0' for the FAD – FADH2 redox couple is nearly 0.05 V. Why is FAD rather than NAD+ the electron acceptor in the reaction catalyzed by succinate dehydrogenase?
Does the complete oxidation of tridecanoic acid (C13:0) make more ATP than the complete oxidation of 9-tetradecenoic acid (C14:1, Δ9) inside human body? Show your calculation.