1) Trypanosomes living in the bloodstream obtain all their energy from glycolysis. They take up glucose from the host’s blood and excrete pyruvate as a waste product. In this part of their life cycle, trypanosomes do not carry out any oxidative phosphorylation, but they do use another oxygen-dependent pathway, which is absent in mammals, to oxidize NADH. a. Why is the oxygen-dependent pathway necessary? b. Would this pathway be necessary if the trypanosome excreted lactate rather than pyruvate? c. Why would the oxygen-dependent pathway be a good target for antiparasitic drugs?

1) Trypanosomes living in the bloodstream obtain all their energy from glycolysis. They take up glucose from the host’s blood and excrete pyruvate as a waste product. In this part of their life cycle, trypanosomes do not carry out any oxidative phosphorylation, but they do use another oxygen-dependent pathway, which is absent in mammals, to oxidize NADH. a. Why is the oxygen-dependent pathway necessary? b. Would this pathway be necessary if the trypanosome excreted lactate rather than pyruvate? c. Why would the oxygen-dependent pathway be a good target for antiparasitic drugs?

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter2: Cell Physiology

Section: Chapter Questions

Problem 10RE: Using the answer code on the right, indicate which form of energy production is being described: 1....

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Which of the following statements is true? A. The NADH dehydrogenase complex can pump more protons than can the cytochrome b-c1 complex. B. The pH in the mitochondrial matrix is higher than the pH in the intermembrane space. C. The proton concentration gradient and the membrane potential across the inner mitochondrial membrane tend to work against each other in driving protons from the intermembrane space into the matrix. D. The difference in proton concentration across the inner mitochondrial membrane has a much larger effect than the membrane potential on the total proton-motive force.
Given that malonate inhibits succinate dehydrogenase which of the following statements is TRUE? a. FADH2 results in only 4 H+ being pumped out of the mitochondrial matrix. b. All electron transport is inhibited. c. Transfer of electrons from NADH to Coenzyme Q (ubiquinone) is inhibited. d. Transfer of electrons from FADH2 to Coenzyme Q (ubiquinone) is inhibited. e. NADH results in only 4 H+ being pumped out of the mitochondrial matrix. Clear my choice
When the cells of our body are in dire need to synthesize Ribose 5 phosphate and it has already enough supply of NADPH, reverse non oxidative pathway of the HMP shunt pathway takes place. If the cell has 10 glucose 6 phosphate molecules, how many of these would be converted to Fructose 6 phosphate and how many to form glyceraldehyde 3 phosphate respectively to synthesize maximum number of Ribose 5 phosphate? 8:2 2:8 4:6 6:4
The complete catabolism of one molecule of C6H12O6 into carbon dioxide and water produces a larger amount of ATP in aerobic prokaryotes than it does in aerobic eukaryotes because aerobic prokaryotes: A. always produce ethanol rather than lactic acid as a byproduct B. generate more molecules of NADH during aerobic respiration C. have no transport costs to get NADH into mitochondria D. generate more molecules of FADH2 during aerobic respiration E. are able to use pyruvate as a substrate for fermentation
a. Starting with acetyl-CoA in the mitochondria, how many ATP molecules are needed to synthesize a 14 C fatty acid? A. 3 B. 6 C. 9 D. 12 b. How many FADH2 molecules will be obtained from the complete oxidation of Myristic acid to CO2 ? A. 13 B. 11 C. 15 D. 17 c. If the complete oxidation of a saturated fatty acid result in the production of 82 ATP molecules, how many ATP molecules will be obtained from a mono-unsaturated fatty acid of similar length? A. 80.5 B. 82 C. 84.5 D. 83.5
When the antibiotic X is added to actively respiring mitochondria, several things happen: the yield of ATP decreases, the rate of O2 consumption increases, heat is released, and the pH gradient across the inner mitochondrial membrane increases. Does X act as an uncoupler or an inhibitor of oxidative phosphorylation? Explain the experimental observations in terms of the antibiotic’s ability to transfer K+ ions across the inner mitochondrial membrane.
Which of the following statements concerning the complete oxidation of FADH2 in the electron transport chain is NOT true? a. In the final step, electrons from cytochrome c to O2 reducing it to H2O in complex IV, and four protons are transported from the intermembrane space to the matrix. b. In the first step, electrons from FADH2 are transferred in complex II to ubiquinone, which does not transport any proton across the inner mitochondrion membrane. c. In the second step, complex III transfers the electrons from ubiquinone to cytochrome c, and four protons are transported from the matrix to the intermembrane space. d. The complete oxidation of FADH2 causes transfer of 6 protons and yields two ATP.
If 30 molecules of acetyl CoA enter into the mitochondria in the presence of O2, how many molecules of ATP will be formed through oxidative phosphorylation?
Which of the following statements is MOST ACCURATE? A. The oxidation of NADH in the mitochondrial matrix results in the transfer of 1 electron to the electron transport chain. B. The reduction of NADH in the mitochondrial matrix results in the transfer of 1 electron to the electron transport chain. C. The reduction of NADH in the mitochondrial matrix results in the transfer of 2 electrons to the electron transport chain. D. The oxidation of NADH in the cytoplasm results in the transfer of 1 electron to the electron transport chain. E. The oxidation of NADH in the mitochondrial matrix results in the transfer of 2 electrons to the electron transport chain.
How come high levels of NADH indicate reduced coenzymes rather than oxidized coenzymes? Isn't pyruvate oxidized by the reduction of NAD+ to NADH? Why is the answer reduced then?
Many amino acids are broken down to intermediates of the citric acid cycle. (a) Why can’t these amino acid “remnants” be directly oxidized to CO2 by the citric acid cycle? (b) Explain why amino acids that are broken down to pyruvate can be completely oxidized by the citric acid cycle.
If oxidation of acetyl-CoA yields 10 ATPs per mole through the citric acid cycle, how many ATPs will be derived from the complete metabolic oxidation of 1 mole of alanine in a mammal? Would the corresponding energy yield in a fish be higher or lower? Why? How much energy would be derived from the metabolic oxidation of 1 mole of isoleucine to CO2, H2O, and NH3? Of tyrosine?