Which of the following statements about peroxisomes is false?

Which of the following statements about peroxisomes is false?

(a) Most peroxisomal proteins are synthesized in the ER.
(b) Peroxisomes synthesize phospholipids for the myelin sheath.
(c) Peroxisomes produce hydrogen peroxide.
(d) Vesicles that bud from the ER can mature into peroxisomes.

Answer: 

Which of the following statements about transport into mitochondria and chloroplasts is false?

Which of the following statements about transport into mitochondria and chloroplasts is false?

(a) The signal sequence on proteins destined for these organelles is recognized by a receptor protein in the outer membrane of these organelles.
(b) After a protein moves through the protein translocator in the outer membrane of these organelles, the protein diffuses in the lumen until it encounters a protein translocator in the inner membrane.
(c) Proteins that are transported into these organelles are unfolded as they are being transported.
(d) Signal peptidase will remove the signal sequence once the protein has been imported into these organelles.

Answer: 

Which of the following statements is true?

Which of the following statements is true?

(a) The signal sequences on mitochondrial proteins are usually at the C-terminus.
(b) Most mitochondrial proteins are not imported from the cytosol but are synthesized inside the mitochondria.
(c) Chaperone proteins in the mitochondria facilitate the movement of proteins across the outer and inner mitochondrial membranes.
(d) Mitochondrial proteins cross the membrane in their native, folded state.

Answer: 

Your friend works in a biotechnology company and has discovered a drug that blocks the ability of Ran to exchange GDP for GTP. What is the most likely effect of this drug on nuclear transport?

Your friend works in a biotechnology company and has discovered a drug that blocks the ability of Ran to exchange GDP for GTP. What is the most likely effect of this drug on nuclear transport?

(a) Nuclear transport receptors would be unable to bind cargo.
(b) Nuclear transport receptors would be unable to enter the nucleus.
(c) Nuclear transport receptors would be unable to release their cargo in the nucleus.
(d) Nuclear transport receptors would interact irreversibly with the nuclear pore fibrils.

Answer: 

A large protein that passes through the nuclear pore must have an appropriate _________.

A large protein that passes through the nuclear pore must have an appropriate _________.

(a) sorting sequence, which typically contains the positively charged amino acids lysine and arginine.
(b) sorting sequence, which typically contains the hydrophobic amino acids leucine and isoleucine.
(c) sequence to interact with the nuclear fibrils.
(d) Ran-interacting protein domain.

Answer: 

Which of the following statements about nuclear transport is true?

Which of the following statements about nuclear transport is true?

(a) mRNAs and proteins transit the nucleus through different types of nuclear pores.
(b) Nuclear import receptors bind to proteins in the cytosol and bring the proteins to the nuclear pores, where the proteins are released from the receptors into the pores for transit into the nucleus.
(c) Nuclear pores have water-filled passages that small, water-soluble molecules can pass through in a nonselective fashion.
(d) Nuclear pores are made up of many copies of a single protein.

Answer: 

What is the role of the nuclear localization sequence in a nuclear protein?

What is the role of the nuclear localization sequence in a nuclear protein?

(a) It is bound by cytoplasmic proteins that direct the nuclear protein to the nuclear pore.
(b) It is a hydrophobic sequence that enables the protein to enter the nuclear membranes.
(c) It aids in protein unfolding so that the protein can thread through nuclear pores.
(d) It prevents the protein from diffusing out of the nucleus through nuclear pores.

Answer: 

Signal sequences that direct proteins to the correct compartment are _________.

Signal sequences that direct proteins to the correct compartment are _________.

(a) added to proteins through post-translational modification.
(b) added to a protein by a protein translocator.
(c) encoded in the amino acid sequence and sufficient for targeting a protein to its correct destination.
(d) always removed once a protein is at the correct destination.

Answer: 

Proteins that are fully translated in the cytosol and lack a sorting signal will end up in ____.

Proteins that are fully translated in the cytosol and lack a sorting signal will end up in ____.

(a) the cytosol.
(b) the mitochondria.
(c) the interior of the nucleus.
(d) the nuclear membrane.


Answer: 

Proteins that are fully translated in the cytosol do not end up in _______.

Proteins that are fully translated in the cytosol do not end up in _______.

(a) the cytosol.
(b) the mitochondria.
(c) the interior of the nucleus.
(d) transport vesicles.

Answer: 

Where are proteins in the chloroplast synthesized?

Where are proteins in the chloroplast synthesized?

(a) in the cytosol
(b) in the chloroplast
(c) on the endoplasmic reticulum
(d) in both the cytosol and the chloroplast

Answer: 

Which of the following statements is true?

Which of the following statements is true?

(a) Lysosomes are believed to have originated from the engulfment of bacteria specialized for digestion.
(b) The nuclear membrane is thought to have arisen from the plasma membrane invaginating around the DNA.
(c) Because bacteria do not have mitochondria, they cannot produce ATP in a membrane-dependent fashion.
(d) Chloroplasts and mitochondria share their DNA.

Answer: 

Which of the following organelles is not part of the endomembrane system?

Which of the following organelles is not part of the endomembrane system?

(a) Golgi apparatus
(b) the nucleus
(c) mitochondria
(d) lysosomes

Answer: 

Which of the following statements about membrane-enclosed organelles is true?

Which of the following statements about membrane-enclosed organelles is true?

(a) In a typical cell, the area of the endoplasmic reticulum membrane far exceeds the area of plasma membrane.
(b) The nucleus is the only organelle that is surrounded by a double membrane.
(c) Other than the nucleus, most organelles are small and thus, in a typical cell, only about 10% of a cell's volume is occupied by membrane-enclosed organelles; the other 90% of the cell volume is the cytosol.
(d) The nucleus is the only organelle that contains DNA.

Answer: 

Which of the following statements about the endoplasmic reticulum (ER) is false?

Which of the following statements about the endoplasmic reticulum (ER) is false?

(a) The ER is the major site for new membrane synthesis in the cell.
(b) Proteins to be delivered to the ER lumen are synthesized on smooth ER.
(c) Steroid hormones are synthesized on the smooth ER.
(d) The ER membrane is contiguous with the outer nuclear membrane.

Answer: 

In which of the four compartments of a mitochondrion are each of the following located?

In which of the four compartments of a mitochondrion are each of the following located?

A. porin
B. the mitochondrial genome
C. citric acid cycle enzymes
D. proteins of the electron-transport chain
E. ATP synthase
F. membrane transport protein for pyruvate

Answer: 

Below is a list of breakthroughs in energy metabolism in living systems. Which is the correct order in which they are thought to have evolved?

Below is a list of breakthroughs in energy metabolism in living systems. Which is the correct order in which they are thought to have evolved?

A. H2O-splitting enzyme activity
B. light-dependent transfer of electrons from H2S to NADPH
C. the consumption of fermentable organic acids
D. oxygen-dependent ATP synthesis



(a) A, C, D, B
(b) C, A, B, D
(c) B, C, A, D
(d) C, B, A, D

Answer: 

Oxidative phosphorylation, as it occurs in modern eukaryotes, is a complex process that probably arose in simple stages in primitive bacteria. Which mechanism is proposed to have arisen first as this complex system evolved?

Oxidative phosphorylation, as it occurs in modern eukaryotes, is a complex process that probably arose in simple stages in primitive bacteria. Which mechanism is proposed to have arisen first as this complex system evolved?

(a) electron transfers coupled to a proton pump
(b) the reaction of oxygen with an ancestor of cytochrome c oxidase
(c) ATP-driven proton pumps
(d) the generation of ATP from the energy of a proton gradient

Answer: 

Which of the following statements is not true about the possible fates of glyceraldehyde 3-phosphate?

Which of the following statements is not true about the possible fates of glyceraldehyde 3-phosphate?

(a) It can be exported from the chloroplast to the cytosol for conversion into sucrose.
(b) It can be used to make starch, which is stored inside the stroma of the chloroplast.
(c) It can be used as a precursor for fatty acid synthesis and stored as fat droplets in the stroma.
(d) It can be transported into the thylakoid space for use as a secondary electron acceptor downstream of the electron-transport chain.

Answer: 

The enzyme ribulose bisphosphate carboxylase (Rubisco) normally adds carbon dioxide to ribulose 1,5-bisphosphate. However, it will also catalyze a competing reaction in which O2 is added to ribulose 1,5-bisphosphate to form 3-phosphoglycerate and phosphoglycolate. Assume that phosphoglycolate is a compound that cannot be used in any further reactions. If O2 and CO2 have the same affinity for Rubisco, which of the following is the lowest ratio of CO2 to O2 at which a net synthesis of sugar can occur?

The enzyme ribulose bisphosphate carboxylase (Rubisco) normally adds carbon dioxide to ribulose 1,5-bisphosphate. However, it will also catalyze a competing reaction in which O2 is added to ribulose 1,5-bisphosphate to form 3-phosphoglycerate and phosphoglycolate. Assume that phosphoglycolate is a compound that cannot be used in any further reactions. If O2 and CO2 have the same affinity for Rubisco, which of the following is the lowest ratio of CO2 to O2 at which a net synthesis of sugar can occur?

(a) 1:3
(b) 1:2
(c) 3:1
(d) 2:1

Answer: 

If you add a compound to illuminated chloroplasts that inhibits the NADP+ reductase, NADPH generation ceases, as expected. However, ferredoxin does not accumulate in the reduced form because it is able to donate its electrons not only to NADP+ (via NADP+ reductase) but also back to the cytochrome b6-f complex. Thus, in the presence of the compound, a "cyclic" form of photosynthesis occurs in which electrons flow in a circle from ferredoxin, to the cytochrome b6-f complex, to plastocyanin, to photosystem I, to ferredoxin. What will happen if you now also inhibit photosystem II?

If you add a compound to illuminated chloroplasts that inhibits the NADP+ reductase, NADPH generation ceases, as expected. However, ferredoxin does not accumulate in the reduced form because it is able to donate its electrons not only to NADP+ (via NADP+ reductase) but also back to the cytochrome b6-f complex. Thus, in the presence of the compound, a "cyclic" form of photosynthesis occurs in which electrons flow in a circle from ferredoxin, to the cytochrome b6-f complex, to plastocyanin, to photosystem I, to ferredoxin. What will happen if you now also inhibit photosystem II?

(a) Less ATP will be generated per photon absorbed.
(b) ATP synthesis will cease.
(c) Plastoquinone will accumulate in the oxidized form.
(d) Plastocyanin will accumulate in the oxidized form.


Answer: 

If you shine light on chloroplasts and measure the rate of photosynthesis as a function of light intensity, you get a curve that reaches a plateau at a fixed rate of photosynthesis, x, as shown in Figure Q14-62. Which of the following conditions will increase the value of x?

If you shine light on chloroplasts and measure the rate of photosynthesis as a function of light intensity, you get a curve that reaches a plateau at a fixed rate of photosynthesis, x, as shown in Figure Q14-62.
Which of the following conditions will increase the value of x?

(a) increasing the number of chlorophyll molecules in the antenna complexes
(b) increasing the number of reaction centers
(c) adding a powerful oxidizing agent
(d) decreasing the wavelength of light used

Answer: 

The photosystems in chloroplasts contain hundreds of chlorophyll molecules, most of which are part of _______________.

The photosystems in chloroplasts contain hundreds of chlorophyll molecules, most of which are part of _______________.

(a) plastoquinone.
(b) the antenna complex.
(c) the reaction center.
(d) the ferredoxin complex.

Answer: 

In the electron-transport chain in chloroplasts, ________-energy electrons are taken from __________.

In the electron-transport chain in chloroplasts, ________-energy electrons are taken from __________.

(a) high; H2O.
(b) low; H2O.
(c) high; NADPH.
(d) low; NADPH.

Answer: 

Stage 2 of photosynthesis, sometimes referred to as the dark reactions, involves the reduction of CO2 to produce organic compounds such as sucrose. What cofactor is the electron donor for carbon fixation?

Stage 2 of photosynthesis, sometimes referred to as the dark reactions, involves the reduction of CO2 to produce organic compounds such as sucrose. What cofactor is the electron donor for carbon fixation?

(a) H2O
(b) NADH
(c) FADH2
(d) NADPH

Answer: 

The ATP synthase found in chloroplasts is structurally similar to the ATP synthase in mitochondria. Given that ATP is being synthesized in the stroma, where will the F0 portion of the ATP synthase be located?

The ATP synthase found in chloroplasts is structurally similar to the ATP synthase in mitochondria. Given that ATP is being synthesized in the stroma, where will the F0 portion of the ATP synthase be located?

(a) thylakoid space
(b) stroma
(c) inner membrane
(d) thylakoid membrane

Answer: 

In stage 1 of photosynthesis, a proton gradient is generated and ATP is synthesized. Where do protons become concentrated in the chloroplast?

In stage 1 of photosynthesis, a proton gradient is generated and ATP is synthesized. Where do protons become concentrated in the chloroplast?

(a) thylakoid space
(b) stroma
(c) inner membrane
(d) thylakoid membrane

Answer: 

Photosynthesis is a process that takes place in chloroplasts and uses light energy to generate high-energy electrons, which are passed along an electron-transport chain. Where are the proteins of the electron-transport chain located in chloroplasts?

Photosynthesis is a process that takes place in chloroplasts and uses light energy to generate high-energy electrons, which are passed along an electron-transport chain. Where are the proteins of the electron-transport chain located in chloroplasts?

(a) thylakoid space
(b) stroma
(c) inner membrane
(d) thylakoid membrane

Answer: 

Which of the following statements about cytochrome c is true?

Which of the following statements about cytochrome c is true?

(a) Cytochrome c shuttles electrons between the NADH dehydrogenase complex and cytochrome c reductase complex.
(b) When cytochrome c becomes reduced, two cysteines (sulfur-containing amino acids) become covalently bound to a heme group.
(c) The pair of electrons accepted by cytochrome c are added to the porphyrin ring of the bound heme group.
(d) Cytochrome c is the last protein in the electron-transport chain, passing its electrons directly to molecular oxygen, a process that reduces O2 to H2O.

Answer: 

Which of the following is not an electron carrier that participates in the electron-transport chain?

Which of the following is not an electron carrier that participates in the electron-transport chain?

(a) cytochrome
(b) quinone
(c) rhodopsin
(d) copper ion

Answer: 

Which of the following statements is true?

Which of the following statements is true?

(a) Ubiquinone is a small, hydrophobic protein containing a metal group that acts as an electron carrier.
(b) A 2Fe2S iron-sulfur center carries one electron, whereas a 4Fe4S center carries two.
(c) Iron-sulfur centers generally have a higher redox potential than do cytochromes.
(d) Mitochondrial electron carriers with the highest redox potential generally contain copper ions and/or heme groups.

Answer: 

Cytochrome c oxidase is an enzyme complex that uses metal ions to help coordinate the transfer of four electrons to O2. Which metal atoms are found in the active site of this complex?

Cytochrome c oxidase is an enzyme complex that uses metal ions to help coordinate the transfer of four electrons to O2. Which metal atoms are found in the active site of this complex?

(a) two iron atoms
(b) one iron atom and one copper atom
(c) one iron atom and one zinc atom
(d) one zinc atom and one copper atom

Answer: 

Which of the following reactions has a sufficiently large free-energy change to enable it to be used, in principle, to provide the energy needed to synthesize one molecule of ATP from ADP and Pi under standard conditions? See Table Q14-47. Recall that

Which of the following reactions has a sufficiently large free-energy change to enable it to be used, in principle, to provide the energy needed to synthesize one molecule of ATP from ADP and Pi under standard conditions? See Table Q14-47. Recall that

?G° = -n (0.023) ?E0', and
?E0' = E0' (acceptor) - E0' (donor).

(a) the reduction of a molecule of pyruvate by NADH
(b) the reduction of a molecule of cytochrome b by NADH
(c) the reduction of a molecule of cytochrome b by reduced ubiquinone
(d) the oxidation of a molecule of reduced ubiquinone by cytochrome c

Answer: 

Electron-transfer reactions occur rapidly. Which of the following statements best describes how the diffusion of ubiquinone is controlled in order to ensure its proximity to the other enzyme complexes?

Electron-transfer reactions occur rapidly. Which of the following statements best describes how the diffusion of ubiquinone is controlled in order to ensure its proximity to the other enzyme complexes?

(a) Ubiquinone is anchored directly in the inner mitochondrial membrane via its hydrocarbon tail, and can only diffuse laterally.
(b) Ubiquinone is present at high concentrations, minimizing the impact of diffusion on the electron-transport chain.
(c) Ubiquinone becomes covalently attached to the other enzyme complexes.
(d) The intermembrane space in the mitochondrion is relatively small, and therefore the random diffusion of these molecules is not a problem.

Answer: 

Ubiquinone is one of two mobile electron carriers in the electron-transport chain. Where does the additional pair of electrons reside in the reduced ubiquinone molecule?

Ubiquinone is one of two mobile electron carriers in the electron-transport chain. Where does the additional pair of electrons reside in the reduced ubiquinone molecule?

(a) The electrons are added directly to the aromatic ring.
(b) The electrons are added to each of two ketone oxygens on the aromatic ring.
(c) The electrons are added to the hydrocarbon tail, which hides them inside the membrane bilayer.
(d) Both electrons, and one proton, are added to a single ketone oxygen bound to the aromatic ring.

Answer: 

Which ratio of NADH to NAD+ in solution will generate the largest positive redox potential?

Which ratio of NADH to NAD+ in solution will generate the largest positive redox potential?

(a) 1:10
(b) 10:1
(c) 1:1
(d) 5:1

Answer: 

Which of the following statements is true?

Which of the following statements is true?

(a) Only compounds with negative redox potentials can donate electrons to other compounds under standard conditions.
(b) Compounds that donate one electron have higher redox potentials than those compounds that donate two electrons.
(c) The ?E0' of a redox pair does not depend on the concentration of each member of the pair.
(d) The free-energy change, ?G, for an electron-transfer reaction does not depend on the concentration of each member of a redox pair.

Answer: 

Which of the following statements about "redox potential" is true?

Which of the following statements about "redox potential" is true?

(a) Redox potential is a measure of a molecule's capacity to strip electrons from oxygen.
(b) For molecules that have a strong tendency to pass along their electrons, the standard redox potential is negative.
(c) The transfer of electrons from cytochrome c oxidase to oxygen has a negative redox potential.
(d) A molecule's redox potential is a measure of the molecule's capacity to pass along electrons to oxygen.

Answer: 

Experimental evidence supporting the chemiosmotic hypothesis was gathered by using artificial vesicles containing a protein that can pump protons in one direction across the vesicle membrane to create a proton gradient. Which protein was used to generate the gradient in a highly controlled manner?

Experimental evidence supporting the chemiosmotic hypothesis was gathered by using artificial vesicles containing a protein that can pump protons in one direction across the vesicle membrane to create a proton gradient. Which protein was used to generate the gradient in a highly controlled manner?

(a) cytochrome c oxidase
(b) NADH dehydrogenase
(c) cytochrome c
(d) bacteriorhodopsin


Answer: 

NADH and FADH2 carry high-energy electrons that are used to power the production of ATP in the mitochondria. These cofactors are generated during glycolysis, the citric acid cycle, and the fatty acid oxidation cycle. Which molecule below can produce the most ATP? Explain your answer.

NADH and FADH2 carry high-energy electrons that are used to power the production of ATP in the mitochondria. These cofactors are generated during glycolysis, the citric acid cycle, and the fatty acid oxidation cycle. Which molecule below can produce the most ATP? Explain your answer.

(a) NADH from glycolysis
(b) FADH2 from the fatty acid cycle
(c) NADH from the citric acid cycle
(d) FADH2 from the citric acid cycle

Answer: 

In a resting muscle, the concentrations of ATP, ADP, and Pi are approximately 0.005 M, 0.001 M, and 0.010 M, respectively. At [Pi] = 0.010 M, what will be the ratio of [ATP] to [ADP] at equilibrium?

The relationship of free-energy change (?G) to the concentrations of reactants and products is important because it predicts the direction of spontaneous chemical reactions. Consider, for example, the hydrolysis of ATP to ADP and inorganic phosphate (Pi). The standard free-energy change (?G°) for this reaction is -7.3 kcal/mole. The free-energy change depends on concentrations according to the following equation:

?G = ?G° + 1.42 log10 ([ADP] [Pi]/[ATP])

In a resting muscle, the concentrations of ATP, ADP, and Pi are approximately 0.005 M, 0.001 M, and 0.010 M, respectively. At [Pi] = 0.010 M, what will be the ratio of [ATP] to [ADP] at equilibrium?

(a) 1.38 × 106
(b) 1
(c) 7.2 × 10-8
(d) 5.14

Answer: 

In a resting muscle, the concentrations of ATP, ADP, and Pi are approximately 0.005 M, 0.001 M, and 0.010 M, respectively. What is the ?G for ATP synthesis in resting muscle?

The relationship of free-energy change (?G) to the concentrations of reactants and products is important because it predicts the direction of spontaneous chemical reactions. In the hydrolysis of ATP to ADP and inorganic phosphate (Pi), the standard free-energy change (?G°) is -7.3 kcal/mole. The free-energy change depends on concentrations according to the following equation:

?G = ?G° + 1.42 log10 ([ADP] [Pi]/[ATP])

In a resting muscle, the concentrations of ATP, ADP, and Pi are approximately 0.005 M, 0.001 M, and 0.010 M, respectively. What is the ?G for ATP synthesis in resting muscle?

(a) -6.01 kcal/mole
(b) 5.88 kcal/mole
(c) 8.72 kcal/mole
(d) 11.1 kcal/mole


Answer: 

In a resting muscle, the concentrations of ATP, ADP, and Pi are approximately 0.005 M, 0.001 M, and 0.010 M, respectively. What is the ?G for ATP hydrolysis in resting muscle?

The relationship of free-energy change (?G) to the concentrations of reactants and products is important because it predicts the direction of spontaneous chemical reactions. In the hydrolysis of ATP to ADP and inorganic phosphate (Pi), the standard free-energy change (?G°) is -7.3 kcal/mole. The free-energy change depends on concentrations according to the following equation:

?G = ?G° + 1.42 log10 ([ADP] [Pi]/[ATP])

In a resting muscle, the concentrations of ATP, ADP, and Pi are approximately 0.005 M, 0.001 M, and 0.010 M, respectively. What is the ?G for ATP hydrolysis in resting muscle?

(a) -11.1 kcal/mole
(b) -8.72 kcal/mole
(c) 6.01 kcal/mole
(d) -5.88 kcal/mole


Answer:

Bongkrekic acid is an antibiotic that inhibits the ATP/ADP transport protein in the inner mitochondrial membrane. Which of the following will allow electron transport to occur in mitochondria treated with bongkrekic acid?

Bongkrekic acid is an antibiotic that inhibits the ATP/ADP transport protein in the inner mitochondrial membrane. Which of the following will allow electron transport to occur in mitochondria treated with bongkrekic acid?

(a) placing the mitochondria in anaerobic conditions
(b) adding FADH2
(c) making the inner membrane permeable to protons
(d) inhibiting the ATP synthase

Answer: 

The mitochondrial ATP synthase consists of several different protein subunits. Which subunit binds to ADP + Pi and catalyzes the synthesis of ATP as a result of a conformational change?

The mitochondrial ATP synthase consists of several different protein subunits. Which subunit binds to ADP + Pi and catalyzes the synthesis of ATP as a result of a conformational change?

(a) transmembrane H+ carrier
(b) F1 ATPase head
(c) peripheral stalk
(d) central stalk


Answer: 

Which of the following types of ion movement might be expected to require co-transport of protons from the mitochondrial intermembrane space to the matrix, inasmuch as it could not be driven by the membrane potential across the inner membrane?

Which of the following types of ion movement might be expected to require co-transport of protons from the mitochondrial intermembrane space to the matrix, inasmuch as it could not be driven by the membrane potential across the inner membrane? (Assume that each ion being moved is moving against its concentration gradient.)

(a) import of Ca2+ into the matrix from the intermembrane space
(b) import of acetate ions into the matrix from the intermembrane space
(c) exchange of Fe2+ in the matrix for Fe3+ in the intermembrane space
(d) exchange of ATP from the matrix for ADP in the intermembrane space

Answer: 

Which of the following statements is true?

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.

Answer: 

In oxidative phosphorylation, ATP production is coupled to the events in the electron-transport chain. What is accomplished in the final electron-transfer event in the electron-transport chain?

In oxidative phosphorylation, ATP production is coupled to the events in the electron-transport chain. What is accomplished in the final electron-transfer event in the electron-transport chain?

(a) OH- is oxidized to O2
(b) pyruvate is oxidized to CO2
(c) O2 is reduced to H2O
(d) NAD+ is reduced to NADH

Answer: 

Which component of the electron-transport chain is required to combine the pair of electrons with molecular oxygen?

Which component of the electron-transport chain is required to combine the pair of electrons with molecular oxygen?

(a) cytochrome c
(b) cytochrome b-c1 complex
(c) ubiquinone
(d) cytochrome c oxidase

Answer: 

Which of the following components of the electron-transport chain does not act as a proton pump?

Which of the following components of the electron-transport chain does not act as a proton pump?

(a) NADH dehydrogenase
(b) cytochrome c
(c) cytochrome c reductase
(d) cytochrome c oxidase

Answer: