Oxidative phosphorylation generates ATP using the reducing power of [ Select ] ["NADH, FADH2", "malate", "", ""] to move electrons down a series of carriers to ultimately produce a [ Select ] ["phosphate gradient", "proton gradient"] across the inner mitochondrial membrane, which is used by ATP synthase to make ATP.  ATP synthase harnesses the energy stored in both [ Select ] ["charge and concentration gradients", "electrostatic and van der Waals interactions"] to achieve high energy phosphate bond synthesis.  If the ion gradient across the inner membrane is dissipated by the expression of UCP1, ATP is not synthesized and [ Select ] ["heat is generated", "electron transport is blocked"] .  The final electron acceptor in the electron transport chain is [ Select ] ["oxygen", "carbon dioxide"] with water as a product.

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.

The four complexes of the electron transport chain use the energy of electrons stored in reducing agents to create a concentration gradient of protons (H*) across the mitochondrial inner membrane. Give the number of protons pumped into the intermembrane space by each of the four complexes: complex I: complex II: complex III: complex IV:

The electron-transport chain consists of a number of multi protein complexes, which work in conjunction to pass electrons from an electron carrier, such as NADH, to O2. What is the role of these complexes in ATP synthesis? It has been demonstrated that respiration supercomplexes contain all the protein components necessary for respiration. Why is this beneficial for ATP synthesis, and what is one way that the existence of super complexes has been demonstrated experimentally? Coenzyme Q (CoQ) is not a protein, but a small, hydrophobic molecule. Why is it important for the functioning of the electron transport chain that CoQ is a hydrophobic molecule?

The following statements describe the path of electrons from NADH through the electron transport chain. Please arrange them in order: Cytochrome c (Fe2+) carries electrons to Complex IV. Cytochrome c (Fe3+) is reduced to cytochrome c (Fe2+) QH2 carries electrons to Complex III Oxygen is reduced to water Ubiquinone (coenzyme Q) is reduced to ubiquinol (QH2)

how many net ATP molecules does the citric acid cycle generate in total? Consider both ATP generated directly by the citric acid cycle and ATP generated downstream in oxidative phosphorylation using other molecuies generated by the citric acid cycle For your answer, consider ATP and GTP to be equivalent A) 32 B) 20 C) 2 D) 10 E) 1

Fatty acid oxidation for energy yield occurs in the mitochondrial matrix, and for palmitate as one example, generates [FADN2, NADH, and Acetyle-CoA or FADH, GTP, and NADPH]  , all of which can be converted to ATP (108 of them to be exact) via oxidative phosphorylation.  This is a [greater or smaller]  yield of ATP per carbon atom compared to glucose.  Ketogenesis is a process where acetyl-CoA (including that from breakdown of fatty acids) is converted to ketone bodies under conditions where carbohydrates are [in excess or liminting]  .  Acetoacetate and D-beta-hydroxybutyrate are delivered from liver to the blood stream where they  provide energy for [cardiac and skeletal muscle as well as brain or synthesis of glycogen]  . [Insulin or glucagon]  promotes ketogenesis by stimulating fatty acid export from adipose tissue.

When pure reduced cytochrome c is added to carefully prepared mitochondria along with ADP, Pi, antimycin A, and oxygen, the cytochrome c becomes oxidized, and ATP is formed, with a P/O ratio approaching 1.0.(a) Indicate the probable flow of electrons in this system.(b) Why was antimycin A added?(c) What does this experiment tell you about the location of coupling sitesfor oxidative phosphorylation?(d) Write a balanced equation for the overall reaction (including cyt c oxidation and ATP synthesis).(e) Calculate ΔG°′ for the above reaction, using E′0 values from Table 14.1and a ΔG°′ value for ATP hydrolysis of -32.2 kJ/mol.

In mitochondria, the respiratory chain converts the potential energy of oxidized carbon into an electrochemical gradient that drives oxidative phosphorylation. Identify the full biochemical names for each of the four complexes of the respiratory chain. Intermembrane space H+ Q NADH NAD+H+ H+ FADH₂ FAD + H+ III II Q III cyt c cyt c H+ H₂O IV Answer Bank Matrix H+ H+ IV H₂O succinate dehydrogenase complex NADH dehydrogenase complex cytochrome oxidase cytochrome bc1 complex

Based on your knowiedge of oxidative phosphorylation, answer the following questions: a) Suppose you synthesize an ATP synthase that was devoid of the y (gamma) subunit. How would the catalytic sites of the B subunits of such an enzyme compare to one another? Why? What if only the c-terminus of the y subunit is missing?