Question 1

In addition to iron,what metal is found in certain cytochromes?

Accepted Answer

Copper is found in certain cytochromes, particularly in cytochrome c oxidase which is involved in the electron transport chain during cellular respiration.

Question 2

Which of the following correctly indicates the number of protons pumped into the intermembrane space at each complex of electron transport for each FADH₂ that is oxidized by the electron transport pathway?

Accepted Answer

D

Question 3

What is the approximate free energy for transporting a mole of protons from the matrix to the intermembrane space under normal conditions within the mitochondria?

Accepted Answer

The approximate free energy for transporting a mole of protons from the matrix to the intermembrane space under normal conditions within the mitochondria is +21 kJ/mol. This value is derived from the proton motive force across the mitochondrial membrane, which is a combination of the chemical gradient (pH difference) and the electrical gradient (voltage difference).

Question 4

Which of the following pathways takes place primarily within the inner mitochondrial membrane?

Accepted Answer

Electron transport takes place primarily within the inner mitochondrial membrane, while fatty acid oxidation, citric acid cycle, and pentose phosphate pathway occur in the mitochondrial matrix. Glycolysis takes place in the cytoplasm outside of the mitochondria.

Question 5

__________ increases oxygen consumption while decreasing ATP synthesis,but ____________ decreases both oxygen consumption and ATP synthesis.

Accepted Answer

Rotenone, azide, antimycin A, and cyanide are all inhibitors of the electron transport chain, which ultimately results in a decrease in ATP synthesis. Valinomycin and nigericin are ionophores that disrupt the proton gradient and ultimately increase oxygen consumption. 2,4-dinitrophenol is an uncoupling agent that increases oxygen consumption by disrupting the proton gradient and decreasing ATP synthesis, while oligomycin is an inhibitor of ATP synthase, which results in a decrease in both oxygen consumption and ATP synthesis. Thus, the only choice that decreases both oxygen consumption and ATP synthesis is D) 2,4-dinitrophenol;oligomycin.

Question 6

Rotation of the ____ subunit causes the _____ subunit to change from tight conformation where ATP is produced to open conformation where ATP is released.

Accepted Answer

The rotation of the γ subunit causes the β subunit to change from tight conformation where ATP is produced to open conformation where ATP is released. This is the mechanism of ATP synthase in oxidative phosphorylation. Choice A, C, D, and E do not accurately describe the correct subunits involved in the mechanism.

Question 7

Which of the following describes a correct and complete electron transfer pathway?

Accepted Answer

The correct pathway for electron transfer in the electron transport chain starts with NADH donating electrons to Complex I, then to Coenzyme Q (CoQ), followed by Complex III, cytochrome c (cyt c), and finally Complex IV. This sequence accurately reflects the flow of electrons from NADH through the main components of the electron transport chain to ultimately reduce oxygen to water.

Question 8

In the malate/aspartate shuttle,glutamate is converted to _________ in the mitochondria while aspartate is converted to ___________ in the cytosol.

Accepted Answer

The answer of In the malate/aspartate shuttle,glutamate is converted to...

Question 9

Which of the following acts as an uncoupler of the mitochondrial proton gradient due to its action as an ionophore?

Accepted Answer

The answer of Which of the following acts as an...

Question 10

Within the electron transport chain,complex _____ represents the entry point for electrons from NADH while complex _____ represents the entry point for electrons from FADH₂.

Accepted Answer

Complex I is the entry point for electrons from NADH, and Complex II is the entry point for electrons from FADH2.

Question 11

The presence of 10 copies of the c subunit of the F₀ complex of yeast ATP synthase allows for the synthesis of 1 ATP for every ______ proton(s)that are translocated across the inner mitochondrial membrane.

Accepted Answer

The presence of 10 copies of the c subunit in the yeast ATP synthase complex means that for each full rotation of the c-ring, 10 protons are translocated. Since one full rotation results in the synthesis of 3 ATP molecules, it takes 10/3 protons to synthesize 1 ATP, which is approximately 3.3 protons per ATP.

Question 12

Which of the following steps in the catalytic cycle of the F₁ component is the most energetically unfavorable?

Accepted Answer

The answer of Which of the following steps in the...

Question 13

What is the approximate P/O ratio if the source of electrons for the electron transport chain is FADH₂?

Accepted Answer

The answer of What is the approximate P/O ratio if...

Question 14

The oxidized form of coenzyme Q is considered a _______ while the reduced form is considered a _______.

Accepted Answer

The oxidized form of coenzyme Q is a quinone because it has a double bond in its ring structure, whereas the reduced form is a hydroquinone because it has two hydroxyl groups.

Question 15

Which of the following correctly describes what happens in the first stage of the Q cycle,considering that one cytochrome c is reduced in the process?

Accepted Answer

In the first stage of the Q cycle, one ubiquinol (QH2) molecule is oxidized to ubiquinone (Q), releasing two protons into the intermembrane space, while simultaneously, another Q molecule is reduced to semiquinone (Q.-), which is a partially reduced form of Q. This process contributes to the reduction of one cytochrome c molecule.

Question 16

Based on the following information,what is the $\Delta$GS1U1P1$\circ$S1S1P0' for the oxidation of malate by NAD⁺? NAD⁺ + H⁺ + 2e^- NADH $~~~~~~~~$$~~~~~~~~$ES1U1P1$\circ$S1S1P0'= -0.32 V Oxaloacetate + 2H⁺ + 2e^- malate $~~~~~~~~$ES1U1P1$\circ$S1S1P0' = -0.17 V

Accepted Answer

The answer of Based on the following information,what is the...

Question 17

Which amino acid is complexed to iron-sulfur clusters to enable them to associate with proteins?

Accepted Answer

Cysteine is the amino acid that can form covalent disulfide bonds and is commonly found in iron-sulfur clusters, enabling them to associate with proteins.

Question 18

If the following two reactions were coupled,what would be the oxidizing agent for the spontaneous reaction? NAD⁺ + H⁺ + 2e^- NADH $~~~~~~~~$$~~~~~~~~$ES1U1P1$\circ$S1S1P0' = -0.32 V Acetaldehyde + 2H⁺ + 2e^- ethanol $~~~~~~~~$ES1U1P1$\circ$S1S1P0' = -0.20 V

Accepted Answer

The answer of If the following two reactions were coupled,what...

Question 19

The inhibition by an unknown inhibitor of electron transport was found to be removed by a large concentration of phenazine methosulfate.Since phenazine methosulfate is known to accept electrons from cytochrome b of complex III,which of the following is most similar to the unknown inhibitor?

Accepted Answer

Antimycin A is the correct answer because it specifically inhibits electron transport at complex III by binding to cytochrome c reductase, which is similar to the effect of the unknown inhibitor that can be alleviated by phenazine methosulfate, a compound known to accept electrons from cytochrome b of complex III.

Question 20

Which of the following uses the energy of the proton gradient to drive transport of its substrates?

Accepted Answer

All the listed transport systems utilize the energy of the proton gradient to drive the transport of their substrates across the mitochondrial membrane, which is a fundamental aspect of cellular metabolism and energy production.

Quiz 15: Electron Transport, oxidative Phosphorylation, and Oxygen Metabolism

In addition to iron,what metal is found in certain cytochromes?

Which of the following correctly indicates the number of protons pumped into the intermembrane space at each complex of electron transport for each FADH₂ that is oxidized by the electron transport pathway?

What is the approximate free energy for transporting a mole of protons from the matrix to the intermembrane space under normal conditions within the mitochondria?

Which of the following pathways takes place primarily within the inner mitochondrial membrane?

increases oxygen consumption while decreasing ATP synthesis,but __ decreases both oxygen consumption and ATP synthesis.

Rotation of the subunit causes the _ subunit to change from tight conformation where ATP is produced to open conformation where ATP is released.

Which of the following describes a correct and complete electron transfer pathway?

In the malate/aspartate shuttle,glutamate is converted to _ in the mitochondria while aspartate is converted to ___ in the cytosol.

Which of the following acts as an uncoupler of the mitochondrial proton gradient due to its action as an ionophore?

Within the electron transport chain,complex _ represents the entry point for electrons from NADH while complex _ represents the entry point for electrons from FADH₂.

The presence of 10 copies of the c subunit of the F₀ complex of yeast ATP synthase allows for the synthesis of 1 ATP for every ______ proton(s) that are translocated across the inner mitochondrial membrane.

Which of the following steps in the catalytic cycle of the F₁ component is the most energetically unfavorable?

What is the approximate P/O ratio if the source of electrons for the electron transport chain is FADH₂?

The oxidized form of coenzyme Q is considered a _ while the reduced form is considered a _.

Which of the following correctly describes what happens in the first stage of the Q cycle,considering that one cytochrome c is reduced in the process?

Which amino acid is complexed to iron-sulfur clusters to enable them to associate with proteins?

The inhibition by an unknown inhibitor of electron transport was found to be removed by a large concentration of phenazine methosulfate.Since phenazine methosulfate is known to accept electrons from cytochrome b of complex III,which of the following is most similar to the unknown inhibitor?

Which of the following uses the energy of the proton gradient to drive transport of its substrates?

Quiz 15: Electron Transport, oxidative Phosphorylation, and Oxygen Metabolism

In addition to iron,what metal is found in certain cytochromes?

Which of the following correctly indicates the number of protons pumped into the intermembrane space at each complex of electron transport for each FADH2 that is oxidized by the electron transport pathway?

What is the approximate free energy for transporting a mole of protons from the matrix to the intermembrane space under normal conditions within the mitochondria?

Which of the following pathways takes place primarily within the inner mitochondrial membrane?

__________ increases oxygen consumption while decreasing ATP synthesis,but ____________ decreases both oxygen consumption and ATP synthesis.

Rotation of the ____ subunit causes the _____ subunit to change from tight conformation where ATP is produced to open conformation where ATP is released.

Which of the following describes a correct and complete electron transfer pathway?

In the malate/aspartate shuttle,glutamate is converted to _________ in the mitochondria while aspartate is converted to ___________ in the cytosol.

Which of the following acts as an uncoupler of the mitochondrial proton gradient due to its action as an ionophore?

Within the electron transport chain,complex _____ represents the entry point for electrons from NADH while complex _____ represents the entry point for electrons from FADH2.

The presence of 10 copies of the c subunit of the F0 complex of yeast ATP synthase allows for the synthesis of 1 ATP for every ______ proton(s) that are translocated across the inner mitochondrial membrane.

Which of the following steps in the catalytic cycle of the F1 component is the most energetically unfavorable?

What is the approximate P/O ratio if the source of electrons for the electron transport chain is FADH2?

The oxidized form of coenzyme Q is considered a _______ while the reduced form is considered a _______.

Which of the following correctly describes what happens in the first stage of the Q cycle,considering that one cytochrome c is reduced in the process?

Based on the following information,what is the Δ\DeltaΔ G ∘\circ∘ ' for the oxidation of malate by NAD+? NAD+ + H+ + 2e- NADH ~~~~~~~~ ~~~~~~~~ E ∘\circ∘ '= -0.32 V Oxaloacetate + 2H+ + 2e- malate ~~~~~~~~ E ∘\circ∘ ' = -0.17 V

Which amino acid is complexed to iron-sulfur clusters to enable them to associate with proteins?

If the following two reactions were coupled,what would be the oxidizing agent for the spontaneous reaction? NAD+ + H+ + 2e- NADH ~~~~~~~~ ~~~~~~~~ E ∘\circ∘ ' = -0.32 V Acetaldehyde + 2H+ + 2e- ethanol ~~~~~~~~ E ∘\circ∘ ' = -0.20 V

The inhibition by an unknown inhibitor of electron transport was found to be removed by a large concentration of phenazine methosulfate.Since phenazine methosulfate is known to accept electrons from cytochrome b of complex III,which of the following is most similar to the unknown inhibitor?

Which of the following uses the energy of the proton gradient to drive transport of its substrates?

Which of the following correctly indicates the number of protons pumped into the intermembrane space at each complex of electron transport for each FADH₂ that is oxidized by the electron transport pathway?

increases oxygen consumption while decreasing ATP synthesis,but __ decreases both oxygen consumption and ATP synthesis.

Rotation of the subunit causes the _ subunit to change from tight conformation where ATP is produced to open conformation where ATP is released.

In the malate/aspartate shuttle,glutamate is converted to _ in the mitochondria while aspartate is converted to ___ in the cytosol.

Within the electron transport chain,complex _ represents the entry point for electrons from NADH while complex _ represents the entry point for electrons from FADH₂.

The presence of 10 copies of the c subunit of the F₀ complex of yeast ATP synthase allows for the synthesis of 1 ATP for every ______ proton(s) that are translocated across the inner mitochondrial membrane.

Which of the following steps in the catalytic cycle of the F₁ component is the most energetically unfavorable?

What is the approximate P/O ratio if the source of electrons for the electron transport chain is FADH₂?

The oxidized form of coenzyme Q is considered a _ while the reduced form is considered a _.